Whose bias is this? What science cannot tell us about discrimination

An instructive workshop

I once attended a First Aid training at work. At one point the instructor showed us a video about a social experiment run on the streets of London. In the experiment, two actors at different times would lie on the pavement pretending to be unconscious: one of them played a homeless person, the other one a smart dressed businessman. Maybe unsurprisingly, passers-by were much more likely to help the smart dressed actor.

I’m a fan of the scientific method so I appreciated the spirit of the experiment and the data-driven approach to the analysis of discrimination. But then the instructor made a comment that struck me as deeply unfair. The video showed a woman approaching the smart dressed actor asking “Are you OK, Sir?”. The instructor sarcastically remarked: “You see? If you wear a tie you even get to be called Sir”.

I immediately thought: “How do you know she wouldn’t have said the same to the other actor?”. While the experiment clearly demonstrates that people on average discriminate, it says nothing about individuals. It may be that there are people who always discriminate and others who would help everyone, or maybe everyone discriminates sometimes: the experiment wasn’t designed to distinguish between these two scenarios (or the whole spectrum in-between).

The limitations of statistics

In fact, virtually no statistics, survey or experiment can really pinpoint a certain bias to specific individuals. All they can do (when properly analysed) is reveal population-level biases. It’s not even a limit of current studies, it’s a limitation of the current state of our statistical tools¹ and the data available.

To truly tell if a specific individual discriminates we would need to run a test tailored to that person: secretly follow them in their daily life, monitor their actions while they’re exposed to a randomised sequence of sick businessmen and homeless people, while controlling for any other confounding factors. I don’t think such an experiment has ever been run, and for obvious reasons.

The difference between racism and racists

Why am I making this point? Because the confusion between the two levels (individual and population) has deep implications for our conversations as a society. The demonstrable racism, sexism or homophobia still existing in our society doesn’t imply that we can tell whether a stranger is being racist, sexist or homophobic after a few interactions.

There are of course exceptions: some strangers make statements that are unmistakably racist, while for some individuals we have such a large collection of borderline remarks/actions that the evidence becomes overwhelming (curiously Trump would fall in both categories). But these are the exceptions rather then the rule in our day-to-day interactions with people.

Obviously abstaining from quick judgment is not easy: we’re hardwired to assign labels to people, especially when they’re from a “different tribe” than ours. We are also more likely to explain behaviours as being due to a person’s “essence”, rather than situational factors (trait ascription bias). In the end, it all comes down to the fact that we are naturally bad at thinking statistically, in terms of randomness and aggregated phenomena, and we prefer stories about individuals.

My personal takeaway from this

Bias and discrimination are still widespread, but where exactly is hard to tell. We can see aggregate numbers about groups but we can’t see the internal states and motivations of the individuals who are part of them. The more we think in terms of fixing a biased system, rather than blaming an undefined army of bias spreaders, the better.

  1. I guess in principle the concept of counterfactuals in causal inference can answer these questions without the need of running an experiment. But we would still require a huge amount of data about the individual under study, as well as an accurate understanding of causal relationships.

The lesson of nostalgia

For a long time I have been suspicious about the feeling of nostalgia. I think the reason is the following: nostalgia eventually permeates all memories, even the saddest and most negative. Teenage depressions, moments of boredom in childhood, loneliness — wait long enough and you’ll grow fond of even the most depressing experience, just because it’s gone.

In light of this fact, can we really trust nostalgia? Shouldn’t we simply ignore and get over it, if all nostalgia has to tell us is “the past was a better place than the present”? That’s indeed what I have tried to do for a long time: treating it as a symptom of chronic dissatisfaction, a door leading only to melancholy and depression.

But I have recently changed my mind about it. Now I think nostalgia is an invaluable guide that can teach us how to live better. I’ve come to this conclusion slowly, through a process where personal experiences, readings and practices played a role. I would like to explain here this process and what nostalgia represents to me now.

It all begins with sleeping.

The elegant trick of dreaming

Why do we sleep? It was long thought that dreams don’t have any biological/evolutionary function. Under this view, dreams were only “side effects” of REM sleep. However, in the last few years a number of studies have unveiled a much more complex reality. As neuroscientist Matthew Walker explains in “Why we sleep”, dreaming is something very similar to an overnight therapy. When we dream we live again (although in a patchy way) the most emotionally charged experiences we had in our daily life, but in a brain free of stress chemicals. That’s the way Nature found to help us absorb emotionally strong memories without leaving us traumatised.

“Through its therapeutic work at night, REM sleep performed the elegant trick of divorcing the bitter emotional rind from the information-rich fruit”

It’s no coincidence that one of the causes of PTSD (Post-traumatic stress disorder) is the lack of REM sleep, which prevents people from separating the emotion from the trauma memory.

Nostalgia, byproduct of dreams

What has this to do with nostalgia? Walker doesn’t talk about it, but I think there is a clear connection here: nostalgia is one of the byproducts of this therapeutic process applied to our memories¹. Once the memory goes through this “soothing balm”, it is freed from its negative emotional connotations. What’s left are the “positive” emotional aspects, those that didn’t have any stress or problematic colour when we originally lived them (the warmth of the sun on the skin, the unconditioned trust in our parents when we were children, the sense of complicity and understanding). We suddenly like the sad memory, we feel nostalgic, because everything that made it bad is now gone.

So the therapeutic interpretation of dreams can explain where nostalgia comes from. To explain why this makes it a great tool in our lives I first have to introduce another clue to the puzzle. I should explain why I value so much the idea of a “soothing balm” for experiences. I should talk about meditation.

Mindfulness: the greatest pain is self-inflicted

Mindfulness and its buddhist roots are a huge topic that I can’t even try to summarise here. There is one concept that I want to describe though, as it is the key for my argument about nostalgia. This concept is the buddhist idea of “Emptiness”².

Everything in our subject experience is emotionally charged, and we often don’t realise it. Not only our thoughts, but our own mental categories and perceptions are loaded with emotions, both positive and negative, about people, objects and events we interact with. And with emotions come the stories that we tell ourselves about people, objects, events. The result of this endless process is a state of continuous distraction and dissatisfaction: because we never really live, we are always lost in thought. We can’t overcome our inner tension even when the emotions are positive — because they could go away soon, or they could be better…

Emptiness is just this: it’s the idea that what we call reality is mostly constructed in our mind, and what we call the “essence” of things is actually an emotional colour we assign to them. The final purpose of many meditative practices, including Mindfulness, is to detach from this emotional layer and start seeing reality as it is. What happens when this detachment is practised for long enough is — allegedly — something extraordinary: positive and negative feelings fade away and give space to a deep sense of calm and compassion.

From this higher state of mind — which is obviously an ideal reference, never fully or permanently accomplished — it is then possible to choose to go back and live the emotions. This time with more awareness and freedom, without distraction, choosing which one to keep a bit longer and which one to let go.

A window on a possible new life

Maybe now you understand where I am getting at. We unconsciously transform our memories every time we dream or remember, removing their emotionally problematic load. My theory is that the result of this purification is subjectively identical to the buddhist Emptiness. When we feel nostalgia for a memory we are retrospectively experiencing that state of peaceful awareness; it is a window on how we could have lived the past, if only we had been able to live fully the moment and recognise the emptiness of distractions. Hidden in the nostalgia there is a priceless teaching and the motivation to live more intensely.

If only I hadn’t been distracted by the thought of the train to take and that gift to buy, maybe I would have enjoyed a bit longer the sun on my face, that conversation with my brother, the familiar warmth of the day. But I was distracted, lost in thought as usual, and that day will never come back. It will come back in the shape of nostalgia though, which will show me how that day looked like, how sweet its juice was, if I had observed it closely enough. That day won’t come back but nostalgia will, and its teaching will be invaluable.

[1] The therapeutic process is not limited to dreams: I would bet that every time we remember an event we are applying a bit of “smoothing balm” to it.

[2] I am here using the interpretation of Emptiness given by Robert Wright in his excellent book “Why Buddhism is True”.

5 historical facts that blew my mind

I have always loved History. I can get hooked on a history book as if it was a novel, with the extra benefit of gaining a new perspective on the past and its relevance for the present. Here is a list of some of the most surprising insights I learned through my readings, I hope you’ll enjoy it!

1. The first human settlers of Madagascar came from Indonesia, not Africa

Chronological dispersal of Austronesian peoples across the Indo-Pacific per: Chambers, Geoff (2013). “Genetics and the Origins of the Polynesians”. John Wiley & Sons, Inc. (via Wikipedia)

Madagascar is only 400 km away from mainland Africa, and around 7,000 km from Indonesia. Nonetheless, the first human settlers in the island came from the Indonesian archipelago [1], no earlier than 300 B.C.E. It is a jaw-dropping distance for that era, even more so if we think that the same population (the Austronesian peoples) went on to colonise Hawaii and New Zealand in the following centuries. As Wikipedia puts it:

They were the most widespread group of peoples with shared linguistic ancestry prior to the colonial era.

2. Wales was the very last part of the Roman Empire to fall to the barbarians… 800 years after the end of Rome

Pillar of Eliseg in Wales (erected c. 855 A.D.). Magnus Maximus is listed as an ancestor of a medieval Welsh king (from Wikipedia)

I came across this fact by reading The Fall of Rome and the End of Civilization [2]:

“North Wales can lay claim to being the very last part of the Roman empire to fall to the barbarians — when it fell to the English under Edward I in 1282. It seems that it was in these ‘backward’ parts of the empire that people found it easiest to re-establish tribal structures and effective military resistance”.

Obviously, by 1282 Welsh had long abandoned roman customs. However, the idea of a roman legacy was still alive and routinely used by Welsh medieval kings to legitimise their power (e.g. royal genealogies had the late Roman Emperor Maximum Magnus as the founding father of Welsh royal dynasties) [3].

3. The destiny of medieval Europe was decided in a pivotal battle between Asian nomadic tribes

By the mid of the XIII century the Mongols had conquered almost the whole continent of Asia, in one of the most incredible and brutal conquests in history (around 40 million victims [3]). Europe and North Africa now yawned open. The Mongol army had already proven devastating against European armies in Hungary and Poland. The near East was in no better position: the Islamic world, although richer than medieval Europe, was divided and weakened by internal struggles. Even the mighty Persian empire had been crushed by the Mongols in the 1220s, while Baghdad was sacked in 1258.

Map of the clash between Mamluks and Mongols (from Wikipedia)

Only one kingdom stood now between the Mongols and the Mediterranean: the sultanate of Cairo. There was a notable difference between this and other Islamic states at the time: in 1250 Egypt had been taken over by its own slave soldiers, the Mamluks, originally from Central Asia. As Frankopan says [4]:

“With remarkable irony, the new Egyptian overlords were men from similar stock to the Mongols themselves — nomads from the steppes”.

The Mongol and Mamluk armies clashed fiercely in 1260 in Ain Jalut, modern day Israel. In retrospect, we know that what was at stake in this battle was the future of Western Asia and Europe. Again Frankopan summarises it very well:

The Middle Ages in Europe are traditionally seen as the time of Crusades, chivalry and the growing power of the papacy, but all this was little more than a sideshow to the titanic struggles taking place further east. […] All that stood in the way of Mongol control of the Nile, of Egypt’s rich agricultural output and its crucial position as a junction on the trade routes in all directions was an army commanded by men who were drawn from the very same steppes: this was not just a struggle for supremacy, it was the triumph of a political, cultural and social system. The battle for the medieval world was being fought between nomads from Central and eastern Asia.

Had the Mamluks been crushed, the world history would have been very different. Instead, the battle of Ain Jalut was the first major defeat for the Mongols, who would never again reach so far in the West.

4. China was on the verge of starting a colonial empire in the early 1400s, a century before Europe

Woodblock print showing one of the ships from the Ming treasure voyages (early 17th century) (from Wikipedia)

Between 1405 and 1433 China undertook seven maritime expeditions (known as Ming treasure voyages), which reached as far as the Arabian peninsula and East Africa. The purpose of these voyages was to incorporate several foreign countries into China’s tributary system and sphere of influence through military, commercial and political supremacy.

These expeditions quickly made Ming China the first naval power in the World, at a time when the military and wealth gap with pre-colonial Europe was still overwhelming. Had China continued on that path, it could have started an intercontinental colonial empire decades before Spain and Portugal, changing radically the course of history. Instead, the expeditions ended abruptly in 1433 and China turned inward for centuries. Historians debate the reason for this: one possible explanation is the internal rivalry between social classes, with the traditional elite seeing the voyages as a threat to their status and resources [5].

5. The most recent common ancestor of every European (and of non-Europeans of European descent) is only 600 years old

If this dating sounds surprisingly recent, wait until you hear this second bit: everyone who was alive 1,000 years ago in Europe and left descendants who are alive today is also an ancestor of everyone alive in Europe today (the so called identical ancestors point).

Both of these astonishing findings are the result of mathematical calculations [6] rather than genetic studies, which by themselves cannot provide accurate dating because of lack of historical records and genetic data. Although the result is of little practical use (we have no way to know who exactly in the ninth century left ancestors alive today and who didn’t — with few exceptions among historical figures, like Charlemagne, that we know must be a common ancestor of all Europeans alive today), it is a beautiful discovery from a human and philosophical point of view. As Adam Rutherford puts it [7]:

You are of royal descent, because everyone is. You are of Viking descent, because everyone is. You are of Saracen, Roman, Goth, Hun, Jewish descent, because, well you get the idea. All Europeans are descended from exactly the same people, and not that long ago.

[1] Guns, Germs, and Steel: The Fates of Human Societies by Jared Diamond, 1997

[2] The Fall of Rome: And the End of Civilization by Bryan Ward-Perkins, 2005

[3] Britannia: A History of Roman Britain by Frere, Sheppard Sunderland, 1987

[3] The Better Angels of Our Nature: Why Violence Has Declined by Steven Pinker2011

[4] The Silk Roads: A New History of the World by Peter Frankopan, 2015

[5] Why Nations Fail by Daron Acemoglu and James A. Robinson, 2012

[6] Modelling the recent common ancestry of all living humans by Rohde D.L., Olson S., Chang J.T., Nature. 431 (7008): 562–6, 2004

[7] A Brief History of Everyone Who Ever Lived by Adam Rutherford, 2016

7 Science myths debunked

I have collected a list of 7 widespread, alleged “scientific facts” and common misconceptions, with corresponding debunking.

This list is potentially much longer, but I decided to focus on those myths that I have encountered more often around me. It’s fascinating to see how common and persistent some of these cultural memes are: part of the reason must be their elegance and simplicity. The scientific truth is often more complicated — but by no means less elegant.

1. Menstrual synchrony

Myth: women who live/work together experience their menstrual cycle onsets becoming more synchronised together over time.

Truth: only one paper in 1971 measured such effect. All subsequent studies failed to replicate it, while others found methodological flaws in the first study. The scientific consensus is that menstrual synchrony likely does not exist.

2. Clockwise/counter-clockwise toilet flush rotation

Myth: water drains in different directions depending on the hemisphere you are in, because of the Coriolis effect.

Truth: while the Coriolis force does exist, it is not strong enough to affect the sense of rotation in flush toilets or bathtubs, where local factors are typically much more relevant (such as the geometry of the basin). Having said that, the Coriolis force has some real effects on larger scale phenomena like ocean currents and cyclones.

3. Humans evolved from chimpanzees

Myth: homo sapiens evolved from chimpanzees through natural selection over million of years.

Truth: humans and chimpanzees both evolved from a common ancestor who lived in Africa around 7 million years ago. While this primate was definitely very different from modern humans, there is no reason to believe it resembled today’s chimpanzees.

4. Evolution increases organisms’ complexity

Myth: biological evolution is a progression from simpler to more complex organisms.

Truth: evolution does not necessarily lead to an increase in complexity. Whatever works gets selected: sometimes what works is more complex than the starting point, sometimes it is simpler. After all, bacteria are among the most successful organisms on the planet.

5. The twin paradox and Einstein’s relativity

Myth: Einstein’s Special Relativity predicts that if one of two identical twins travels in space at high-speed and then returns home, the twin left on Earth should have aged more than the one who travelled. It’s called a paradox because it is at odds with our intuitive idea that time should pass at the same speed for everyone.

Truth: while the myth is correct in describing the Special Relativity’s prediction, it is wrong in interpreting its “paradoxical” aspect. It is not paradoxical because it is at odds with our intuition, but rather because it seems to contradict one of the principles of Relativity itself (specifically, the principle that all motions are relative, which would imply that time dilation should be the same for both twins). This paradox is only apparent though, and it disappears when you account for accelerations. It’s funny how the myth version of the paradox, which doesn’t even mention acceleration, is in effect an example of the naive interpretation of Relativity that prompts the paradox in the first place.

6. Galileo and flat Earth

This is more a historical rather than scientific misconception, but it’s so widespread that I felt I have to include it.

Myth: Galileo was a promoter of the idea that the Earth is round. He got persecuted because this idea was opposed by the Church. A somehow related myth wants Columbus challenging the idea of a flat Earth by sailing west.

Truth: the fact that the Earth is round has been known in the West since about the VI century BC. This fact wasn’t challenged by religious authorities even throughout the Middle Age, and it remained common knowledge among scholars and intellectuals. The controversy Galileo was involved in was about whether the Sun rotates around the (round) Earth or vice versa. For what concerns Columbus, he challenged the idea that the globe was too large to safely sail to the Far East from Europe (he was wrong, but he got lucky and found another continent on his way).

7. The supercontinent Pangea

Myth: when the ocean formed there was a single large continent, Pangea, which later split into our modern continents.

Truth: Our modern continents did split from Pangea, however this was far from being a first, primordial supercontinent: Pangea itself had formed from the “collision” of disjoint continents, which in turn formed from the division of an older supercontinent (called Rodinia)… and so on. Geologists believe that at least 6 supercontinents succeded since the formation of the Earth.

A map of contradictions in our political conversations

Pointing out a contradiction in someone’s argument is a very popular rhetorical device. You can find this type of technique in the majority of social media debates.

I have never really liked this device, mostly because of its laziness: it doesn’t force you to state your own position (which is the whole point of a debate), and still for some reason it is perceived as a knock-out argument (which of course it is not, otherwise Trump would have exactly zero supporters by now).

But I still think there is value in pointing out contradictions. At least when the objective is auto-analysis and a honest scrutiny of ideas rather than scoring points. A crucial contradiction at the heart of many people’s beliefs can indicate either bad faith or a lack of in-depth thought: either way, it’s a great place to start if we want to make any progress in our conversations.

Below is a list of what I consider the most striking contradictions in today’s political discourse.

A contradiction across the board: free markets, restrained morality (and vice-versa)

There is a bizarre pattern in most people’s political ideas, a pattern so common that we no longer notice it. Most liberals promote a stronger regulation for markets but at the same time a less regulated morality (civil rights, sexual liberation), while most conservatives support market deregulation but at the same time more structured and normative moral customs.

Where does this come from? There is no obvious reason why believing in free markets should make you more likely to believe that gay marriage is a bad idea, and yet these kinds of correlation are everywhere. This widespread pattern simply betrays the tribal nature of our political ideas: we tend to accept the full package at face value because that’s what our group believes in. A widespread inquisitive attitude would necessarily translate into a much broader mosaic of beliefs (e.g. more people believing that both unregulated markets and unregulated moral customs are a good idea).

Far-right: the looming good Samaritan

Far-righters don’t seem to follow this general pattern (they usually support heavy government intervention in both the market process and morality). However they have their own, macroscopic contradiction. The revealing contradiction of the far-right is Christianity. For right-wing nationalists, traditions are a crucial part of a nation’s identity and must be preserved and revitalised. Crucially, this sacred rule encompasses all traditions, irrespective of their content.

This ambitious commitment causes a big problem to western right-wingers when it turns out that one of the traditions to preserve is Christianity. It doesn’t matter how you want to define Christian morality, there is little doubt that it is at odds with almost every single principle (explicit or not) of the far-right ideology: militarism, xenophobia, cult of personality, authoritarianism. The most recent example is immigration, where the far-right politics of closed border is simply irreconcilable with the evangelic message.

The far-right’s answer to this contradiction is to simply ignore it as far as I know, but it’s huge. It is so macroscopic that I can’t stop wondering why it doesn’t undermine more their credibility. It’s truly one of the most unsettling examples of cognitive dissonance.

Incidentally, it’s interesting to note how this wouldn’t be necessarily a contradiction if it wasn’t for the peculiarity of Christianity. Until 380 AD, ancient Romans (and most of the ancient civilisations) could easily embrace their militaristic traditions including their religion, because their gods wouldn’t demand them to turn the other cheek.

Anti-abortion activism: pro-life, unless you need a condom

Anti-abortion activists claim that abortion is equivalent to murder. I don’t doubt they genuinely believe that, unless they are also against contraception. Contraception and sex education are by far the most effective ways to prevent abortions, historically way more effective than anti-abortion laws. If you believe that abortion means killing a baby, you should be out there in the streets distributing condoms.

And yet, the vast majority of pro-life activists oppose birth control and sex education. So, it’s either one of two things: they are genuinely unaware of this big contradiction (again, passive receivers of a ready-made conservative package of beliefs) or they’re operating in bad faith (their real priority being the state control of women’s bodies rather than babies’s lives).

Liberals: Kant’s bastards

In a way, the question of truth is at the heart of the Left’s contradiction.

On one hand, liberals are heirs of the Enlightenment and its ideas of rationality — rather than tradition — being humanity’s supreme guide. Rationality is seen as a fundamental tool for emancipation, which frees not only from the constraints of Nature, but also from the false ideologies of the dominant class (e.g. religion, bigotry, racism, sexism). I will call this the “positivist” component of the Left.

On the other hand (and this is mostly a more recent development) liberals see respect of cultures as a paramount value. This is seen as particularly urgent in an era where colonialism and institutional racism have only recently been overcome or are still an issue, and their wounds and memories are still alive. The idea that no person should be discriminated based on their religion and culture is obviously in no contradiction with the positivist component of the Left (it’s actually a logical consequence of it), but many liberals are now saying something different: we shouldn’t just respect every person in the same way regardless of their culture — we shouldn’t criticise any culture, regardless of the ideas they promote. From this lens, the Enlightenment’s values aren’t intrinsically better than any others. I will call this the “postmodernist” component of the Left.

The contradiction between the positivist and the postmodernist components of the Left is quite clear. If you claim that women should have the same rights as men, then cultures that promote this principle are necessarily better (everything else being equal) than cultures that do not¹. In the impossible attempt of keeping both positions, many liberals come up with relativistic world views like “the emancipation of women is a valuable objective in the cultural frame of the West, but other cultures see it differently and we cannot object to it from the perspective of our culture”. Paradoxically these kinds of view are the most patronising and racist you could come up with.

As the author Ali A. Rizvi summarised in a tweet, “When white people challenged their religious orthodoxies it was called the Enlightenment. When brown people challenge them, it’s called Islamophobia?”

[1] Which obviously doesn’t imply we should “force” any change in the second group of cultures. But that a change would be desirable is a logical consequence, and more desirable than preserving the diversity of cultures for its own sake.

“Europe, A Natural History” by Tim Flannery

What do we think about when we think about Europe? Some might think of history and art, others of football, welfare state, or the horrors of war and genocide. Europe is all these things, but even combining them all we get a very partial view of the old continent. For a simple reason: all these things happened in the last 3,000 years, while Europe has been around for at least 100 million years.

I have just finished reading a great book that sheds light into the little known 99.999% of European history. The book is appropriately titled “Europe: The First 100 Million Years” and is written by the Australian palaeontologist Tim Flannery. It is a fascinating journey into the natural history of Europe, from the era of dinosaurs to modern times.

The book, packed with information, will change the way you think about the old continent. What follows is a selection of the coolest facts and insights I discovered while reading it.

That strange archipelago called Europe

“It is hard to overstate just how unusual Europe was towards the end of the age of the dinosaurs”.

Hatzegopteryx, the largest pterosaurus ever existed (Wikipedia)

100 million years ago Europe was a widely scattered archipelago with a unique fauna. Because of a process known as insular dwarfism, European dinosaurs evolved to be smaller than their relatives in other continents: examples found in Romania are the armoured Struthiosaurus and the duckbilled TelmatosaurusOther animals instead ended up growing bigger because of the absence of predators (island gigantism), such as the terrifying pterosaurus Hatzegopteryxthat had a 12 meter wingspan and looked like a monster from a Stephen King novel.

Midwife toads, salamanders and newts are among the few, unlikely survivors of this era. Truly the oldest Europeans.

“Look a midwife toad in the eyes, and you are looking at a European whose ancestors blinked at the terrible Hatzegopteryx”

Tanzania, Europe

66 million years ago a big asteroid ended the era of dinosaurs. Slowly after it, a European proto-continent began to take shape. This larger and better connected landmass was able to host and grow a more diverse fauna and flora, with continuous exchanges with its neighbours Africa, Asia and North America (the latter was even occasionally connected to Europe before finally drifting apart).

Forests were “as cathedral like as the great forests in Borneo”, while the population of vertebrates grew from small rat-sized mammals to huge, omnivore pig-like creatures known as “hell pigs” and the gigantic bird Gastornis.

The large, flightless bird Gastornis that lived in Western Europe until 45 Million years ago.
The voracious Entelodont, known as hell pig.

Models of Anisodon in Basel (Wikipedia)

The apex and conclusion of this long period is the Miocene era (23 to 5.3 million years ago), “arguably Europe’s most enchanting epoch. A growing land area, enhanced migration corridors, and a favourable climate conspired to create an unprecedented diversity of mammals”. My favourite Miocene beast is the Anisodona large mammal with a horse-like head and a gorilla-like body.

Made in Europe

Europe played a crucial role in fostering the evolution of some very successful and still existing species. Antelopescervines and even the first known apes (as distinct to monkeys) originated in Europe. The latest discoveries reveal that the continent played a crucial role in the evolution of the first hominins.

When the Mediterranean dried up

Artistic representation of the Messinan salinity crisis (Wikipedia)

Around 6 million years ago, at the end of the Miocene, the precursor of the Strait of Gibraltar closed tight. As a result, the Mediterranean dried up quickly and became “a vast salt plain, more than 4000 meters below sea level at its lowest point, dotted with hypersaline lagoons […] where temperatures may have reached 80 degrees Celsius”. When finally the ocean found its way again into the basin, some 600,000 years later, “it must have been an awesome sight that overall would have dwarfed any waterfall existing today”.

The devastating ice age

Europe is the continent whose recent natural history has been most affected by the ice age. The great variety of European vegetation, similar to that of North America and Asia today, was destroyed by the cooling that began 2.5 million years ago. Europe was so inhospitable that humans colonised it 10,000 years after Australia, despite it being much closer to Africa.

One of the most telling consequences of the ice age is the fact that today Mediterranean forests do not host any unique bird species:

“[…] tall forests were so devastated by the ice ages that none of the surviving patches was large enough to support the species of birds that were restricted to them”.

Islands and last survivors

For the rich European fauna though, more devastating than the climate changes was the arrival of humans. It is believed that prehistoric humans were responsible for the extinctions of cave bearscave lionswoolly rhinos and mammoths in the last 30,000 years: the old continent was incredibly wild until the day before yesterday.

The incredible drawings of Chauvet Cave in France, dating back 30,000 years ago
The incredible drawings of Chauvet Cave in France, dating back 30,000 years ago

Intriguingly, European islands were the last refuge for many of these now extinct mammals until historical times. Cyprus hosted miniature hippos and straight-tusked elephants (whose skulls might have inspired ancient mythology), Sardinia and Corsica dwarf mammoths and giant otters, while the Balearic islands had the bizarre Balearian mouse-goat.

Rewilding Europe

Knowing what Europe used to look like until very recently, the author makes the point that repopulating the old continent with wild animals from Africa and Asia would be the most natural thing to do. It would also be ethical, given the need to share the burden of conservation. The book closes with a beautiful image of what it could look like in 200 years if Europe embraced this rewilding path:

“We approach a continent that in one respect looks like the archipelago of old: cities stand out like islands linked with transport corridors […] Instead of being separated by sea, Europe’s cities are separated by vast areas of forests and woodlands […] The lifestyles of the Europeans are very different from those of the rest of the world’s population, which is concentrated in mega-cities without access to wild areas”.

The calibration of feelings

Are brave people brave because they are better at controlling their own fears? Or are they brave because they feel less fear in the first place?

It may seem like an idle and abstract question, but the way we judge and think of people’s character depends on the answer to that question.

And it applies to virtually every personality trait. Are we more melancholic than our jolly friend because we give up more easily to sad thoughts? Or do we experience sad thoughts more intensively?

What intrigues me about this question is that we can never really answer it. In order to compare two people’s feelings (let’s say, the fear of approaching a stranger) we would have to quantify those feelings first. But how do we do it? Even if we ask each person to assign a number to their fear, what we get is always a relative measure. They could both come up with “4 out of 10”, but if the first person is twice as sensitive as the other then his/her “4” is by definition an “8” in the other person’s scale. Our internal thermometers might have completely different calibrations but we never find out because we can only compare the numbers we read on them.

It seems to me we never really acknowledge this ambiguity. We are hardwired to see different characters as different attitudes towards the same quality of experience. It’s a framework that does work in the physical world: if you can lift 50 kg and I lift 25 kg, you’re twice as strong as me in an unambiguous way. The external factor (the weight) can be objectively quantified and what’s left to compare is our bodies’ ability to cope with it.

Internal states do not work like that. And we now have plenty of evidence that suggests this. For example, we know that changes in chemicals in the brain can drastically change the way people experience their life (bipolarism, clinical depression). And we know that traits like introversion and extroversion are closely linked to the degree of reactivity to external stimuli¹.

The consequences of this peculiar arithmetic of feelings are meaningful. If introverts are more sensitive than extroverts, for example, then their being less social has nothing to do with them being less interested in people. It’s just that they “experience” people much more than others, satisfying their social needs (identical to everyone else’s) much faster.

It is a new perspective that would make us less judgemental with other people (and ourselves). We should simply acknowledge that we do not know what each other’s thermometers measure.

[1] More details in the great book “Quiet” by Susan Cain, highly recommended.

Netflix show “Dark” unveils our free will illusion

I have recently finished watching the Netflix series “Dark”, a fascinating and addicting sci-fi thriller whose plot involves a sequence of convoluted and intertwined time travels (no spoilers from here on).

The fascination of this show is the strictly logical and consequential way these time travels unfold and concatenate. There is no room for the grandfather paradoxes that abound in many sci-fi and super-hero movies, where characters travel back in time to change a past they don’t like and succeed (Terminator, Star Trek, The Avengers…). In “Dark” you do find characters driven by this motivation, but they inevitably fail (and in doing so, they often prompt the sequence of events they wanted to prevent in the first place). Most of the twists in the series revolve around this simple principle.

A frustrating Deus Ex Machina

What I found really interesting is the way this consequential approach to time travel — that I rationally recognise as more “correct” because it is logical and paradox-free — instinctively felt wrong and unnatural to me. “Why would you do that?! Can’t you see this would ruin your plan?” is what you will find yourself shouting at the characters over and over again. Some of their actions feel nonsensical and designed by the screenwriters with the only purpose to make them fail and fit the consequential approach. You sense the continuous presence of a Deus Ex Machina that just doesn’t feel realistic.

And yet, I would argue that this sense of dissonance is not Dark’s screenwriters’ problem. It is ours. It is not the result of far-fetched screenwriting; it is the result of our illusory sense of free will. And thinking through this “it doesn’t feel right” sense can give us some powerful insight into the illusion of free will.

Are you so different from a tennis ball?

Let me explain my point by starting with a simple example. Imagine a time travel that only involves inanimate objects: let’s say that a tennis ball travels 10 seconds back in time. Now imagine that, once the ball is in the past, it starts rolling down (because it had ended up on top of a ramp) until it hits the replica of itself that exists in this time line (i.e. the same ball, just 10 seconds younger). As a consequence of the impact the second ball ends up in a time travel machine, which immediately activates (let’s say there is an automatic activation system) and teleports the second ball 10 seconds back, on top of the ramp¹. The ball rolls down, hits its past self… and so on (hopefully the image below makes the whole thing intelligible).

If we assume that things like “time machines” are physically possible, then the whole architecture I described is consistent and logical. It is a toy replica of what I called the “consequential approach” in “Dark”: the future is a cause of what happens in the past, and the past never changes its unfolding as that would otherwise change the future that caused it.

But crucially, and unlike “Dark”, when looking at this example you don’t think “why doesn’t the ball decide to turn left and not hit the past self?”. You don’t ask that because you know that the ball does not have any choice but to follow the laws of physicsBut now my question is: what’s so different when humans are involved in the chain of events?

An uncomfortable (but old) truth

Our brains are incredibly complex systems, but they are undeniably physical systems that obey the deterministic laws of physics². In this respect, they are no different from a tennis ball rolling down a ramp. If we ended up in a similar time travel loop, we wouldn’t be any more able than a ball to break the eternal sequence of travels. And this would happen even if the guy trapped in the eternal loop is trying really hard not to hit his past self: all his plans and thoughts are only sophisticated tennis balls rolling down a ramp, accidental perpetrators of the future which will cause them. There is indeed a Deus Ex Machina here, it is called physics.

“Dark” is a great show because it depicts this inescapable dynamic at a huge scale. What we feel like far-fetched screenwriting is the result of our illusory belief that our brains are somehow above the law of physics. A belief that we have known to be wrong for at least a century. Time travel might be impossible, but it forces us to face this illusion.

[1] Yes, this time machine is also a teleport machine… not the cleanest thought experiment, I grant you, but there is no loss of generality here (i.e. one can easily imagine variants of this example without teleportation).

[2] Quantum mechanics cannot rescue our free will here. For a number of reasons, but the main one is that our cognitive processes are 100% “classical physics”: they can be fully described using the classical theory of electromagnetism.