MoneySupermarket approached me for their Hotel of Mum and Dad campaign about the question of why it’s so difficult for young people to buy a house today. There are many proximate-level economic and social factors to answer this question, but an ultimate-level explanation lies in an extension of our juvenile period – a process that’s been occurring since we became human. The research on this is summarized under the Cultural Brain Hypothesis and Collective Brain. A discussion on Sky News and a copy of the article below:
Sky News interview where I discuss the trend of adults moving back home with their parents and how this links to the Cultural Brain Hypothesis, collective brain, and ever extending juvenile periods.
As parents, we might summarise our role as the three Ps: To Protect, to Provide, and to Prepare. But when our children face an ever-changing, more complex and more challenging world than we faced, how do we prepare our children so that they can provide for and protect themselves? And what happens when life happens, and they need to return home?
There is a trend of adult children moving back in with their parents to save money, at the expense of their privacy and independence.
At an individual level, these decisions are often made with changing life circumstances – health, divorce, losing a job, increases in rent, conflict with flatmates and so on. But there are often broader societal trends underlying these decisions.
The first is a long term trend that has affected humans since the beginning of our species – what scientists call our ‘extended juvenile period’.
Every profession now has to deal with new technologies and more complex systems. This has resulted in us spending more time in education, particularly on-the-job education (e.g. internships, junior roles and lower paid apprenticeships), meaning it now takes more time before we’re earning enough to support a family, buy a house and become self-sufficient.
It used to be that a high school diploma was enough to make a good living. Then it took a university degree or a short apprenticeship. Now it requires post-graduate degrees, internships and volunteer work – which can be unpaid – as well as on-the-job training.
This has meant that the age of first birth, the age of owning a home and the age of financial independence have been steadily rising. As a result, when the last two generations did finally leave home, they often found themselves needing to return, especially if they were unable to share costs with a partner or group of friends.
The second trend is more recent. Economic growth has slowed, yet wealth and income inequality has risen. In combination, this means there’s less to go around per person and of what is there, a greater share has gone to the top end of society.
This means it’s becoming more difficult for people to purchase a home and become self-sufficient than it was for their parents, or even those born a couple of decades earlier.
These are real problems with not-so-simple solutions.
However, it can be hard to see an adult child return home in less than ideal circumstances, especially after two decades of interrupted sleep, changing nappies, helping with homework, giving them lifts from event to event, dealing with the ups and downs of friendships and first romantic relationships, and celebrating the joys, achievements, graduations and first jobs.
For children too, this is often not a preferred situation. They are trading their independence and privacy for financial savings and perhaps some home cooking and laundry.
There are no one-size-fits-all solutions on how to handle the new situation, but it may be worth noting a few things in moving toward a more open discussion:
Emotions such as pride and sense of self-worth are affected on both sides – A child in their ability to handle the world as their parents did, and a parent in whether they properly prepared their children for the world. These may lead to important discussions, but it’s important to remember that the world is more competitive for young adults than ever before.
Different societies and different cultures have different expectations for independence – In many so-called WEIRD (Western Educated Industrialised Rich Democratic) societies, young adults are expected to live alone or apart from their parents. However, in many other societies, unmarried children live with their respective parents until marriage and then married couples live with or near their husband (patrilocal) or wife’s (matrilocal) parents. It may be that our society is moving toward these other norms.
There are pros and cons for both parents and children that vary from family to family, and circumstances outside of the family also affect emotions and mental health – In discussing how long the arrangement will last and how to keep both parties happy, it’s worth remembering the costs and benefits to both parties. On both sides, this can come in the form of increased support at home, the joy of being closer to loved ones and perhaps access to grandchildren, versus the loss of privacy, increased workload, reduced living space and financial costs. An honest conversation can help prevent problems from surfacing in less ideal ways.
Thankfully, many parents have been willing to help their children reduce their expenses by moving back home – even though research has shown the tensions over how much children should be contributing in rent and expenses, and the mismatch in expectations between parents and children.
Hopefully, even if the returns to parents aren’t immediately monetary, they find that their children do eventually become financially self-sufficient and perhaps return the favour as they grow older.
I spent the last few days as a meeting organized by the Templeton World Charity Foundation (TWCF) at the Diverse Intelligences Summer Institute Meeting at University of St Andrews, St Andrews, Scotland. It was an amazing few days of stimulating conversation on intelligence.
I presented work on “Corruption, Cooperation, & the Evolution of
Evil Eye” at the Human Behavior and Evolution Society (HBES) annual conference.
Part of this work was based on a recent paper published in Nature Human Behaviour, with some context published in Evonomics and ProMarket (pre-print). The other part was work in progress on understanding the evolution of evil eye.
I presented work on “Corruption, Cooperation, & the Evolution of Prosocial Institutions”, including some new work on the evolution of evil eye belief and related behaviors at the CIFAR Institutions, Organizations, and Growth program’s annual meeting.
Part of this work was based on a recent paper published in Nature Human Behaviour, with some context published in Evonomics and ProMarket (pre-print). The other part was work in progress on understanding the evolution of evil eye.
PBS has a new 4-part documentary series on First Civilizations; a sequel to their successful series First Peoples. The new series charts the rise of civilization clustered around 4 topics: War, Religion, Cities, and Trade. I’m the key contributor for episode 3 on Cities, which premieres tonight. I travel through Tokyo, Japan discussing innovation, inequality, sociality, and collective brains. A short clip from the episode below:
You can read more about the research behind this episodes in these review papers (written to be accessible to the general reader):
Introduction to Cultural Evolution
Chudek, M., Muthukrishna, M. & Henrich, J. (2015) Cultural Evolution. In Handbook of Evolutionary Psychology, 2nd Edition. Edited by D. M. Buss. [Download]
I also discussed the general approach to understanding corruption using cultural evolution and the science of cooperation – corruption is one scale of cooperation undermining another. For example, nepotism is cooperation at the scale of kin, well explained by inclusive fitness, undermining cooperation at the scale of the formal institution. More on this framework can be found at ProMarket or Evonomics. Finally, I presented some work in progress based on this approach, including some work by my students.
Last week, my paper with Kieran Fox and Susanne Shultz was published in Nature Ecology and Evolution. The paper was a multiyear project, which consisted of countless hours spent poring through marine mammal literature to create the most comprehensive database of cetacean physiology, social structure, life history, and behavior to date. We then used this database to test some of the predictions of the Social Brain and Cultural Brain Hypotheses. Some of the confirmations of these predictions are shown in Figure 3 of the paper below.
Cetaceans represent a great test for the Social Brain and Cultural Brain Hypotheses (CBH), because of how evolutionarily alien these species are, and how strange their underwater world is compared to the world we inhabit. We have previously tested the CBH predictions with primates, but their evolutionary closeness to humans means that the relationships we find may be due to our evolutionary logic or due to these features (such as large brains and high sociality) being present in a common ancestor. Thus finding these relationships in cetaceans is strong evidence for the evolutionary logic. It also sets up cetaceans as an interesting control group for understanding human evolution.
The ongoing massive media response and public interest in marine mammals and the evolutionary sciences was heartwarming. Altmetrics suggested a score of 1026, in the top 5 of articles in Nature Ecology and Evolution, receiving the most attention of recent articles and top 50 of all articles of a similar age. Highlights included several video and audio interviews, including with BBC World News, BBC World Service Radio “Science in Action”, CBC “The Broadcast” (below), and the front page of the print edition of the The Times and front page of the website of The Guardian.
I presented a the “Cultural Evolution of Economics” with some illustrations on how cultural evolution can help economists and how economists can help those interested in cultural evolution. To illustrate this, I presented some recent and upcoming work on cooperation, corruption, democracy and economic growth. Abstract below:
Homo Economicus are extinct or on the verge of extinction, or so it would appear from outside economics. But within economics, reports of their death have been greatly exaggerated. Economicus’ persist, in part because alternative theories of human behavior are not readily integrated into existing economic approaches. To paraphrase Buckminster Fuller, criticism is not sufficient—you need to build a better model. I’ll discuss collaborations at the London School of Economics that are attempting to build that better model by integrating cultural evolutionary theory into economics. A cultural evolutionary approach seats corruption as a special case of cooperation, offering new means to understand and combat it (Muthukrishna, et al., 2017, “Corrupting Cooperation and How Anti-Corruption Strategies May Backfire”, Nature Human Behavior). A cultural evolutionary approach helps identify the invisible cultural pillars that support successful economic and democratic institutions (Stimmler & Muthukrishna, 2017, “When Cooperation Promotes Corruption and Undermines Democracy”, Working Paper; Muthukrishna, et al., in prep, “A WEIRD scale of cultural distance”). A cultural evolutionary approach reveals the relationship between economic growth, inequality, tolerance for inequality, and widespread beliefs—like “evil eye” and witchcraft—that have economic implications (Li & Muthukrishna, 2017, “The coevolution of Economic Growth, Inequality, Tolerance for Inequality, and Belief in Evil Eye”, Working Paper). These related studies reveal how cultural evolution may offer new approaches to age old problems, but also how the economic toolkit may be deployed to understand culturally evolved beliefs and behaviors.
Li presented an economic model and corresponding experimental test on the co-evolution of economic growth, inequality, tolerance for inequality and the widespread belief in “evil eye“.
Introducing the possibility of bribes into an institutional punishment public goods game results in reduced contributions.
In an institutional punishment public goods game, stronger leaders result in more cooperation. In our modified “bribery game”, stronger leaders result in less cooperation.
Anti-corruption measures including transparency and tying leaders payoffs to the success of the public good result improve contributions, except if economic potential is low and leaders are weak. Here, they can actually further reduce contributions.
Culture matters. Exposure to corrupt norms via living in corrupt places increases bribes, but having an ethnic heritage that includes corrupt countries, but not having actually lived there yourself results in less bribery.
Figures 1, 2 and 3, reproduced below illustrate these results.
Raw contributions (of the ten endowed points) and 95% confidence intervals for each within-subject treatment (control, BG, BG with partial transparency or BG with full transparency) in each between-subjects structural context (strong versus weak leader and poor versus rich economic potential). These data are consistent with our theory that predicts that more powerful leaders increase contributions in the IPGG but decrease contributions in the BG.
Darker blue indicates greater public goods provisioning and darker red indicates reduced public goods provisioning. All coefficients were extracted from a single model by changing reference groups. The columns represent the reference group treatment (control versus BG), while each row shows the coefficient of each treatment compared with this reference group. The contributions were z scores, so the coefficients represent s.d. The full model is reported in the Supplementary Information. In all models, we accounted for the clustering inherent in the experimental design by including a fixed effect for the number of subjects and random effects for participants within groups. Note that in all treatments and structural contexts, the BG has lower contributions than the structurally equivalent IPGG (control). Corruption mitigation effectively increases contributions (although not to control levels) when leaders are strong or the economic potential is rich. When leaders are weak and the economic potential is poor, the apparent corruption mitigation strategy, full transparency has no effect and partial transparency further decreases contributions. *P < 0.10; **P < 0.05; ***P < 0.01; ****P < 0.001.
Odds ratios and 95% confidence intervals are shown for each behaviour (accept bribe, punish or do nothing).
There is nothing natural1 about democracy. There is nothing natural about living in communities with complete strangers. There is nothing natural about large-scale anonymous cooperation. Yet, this morning, I bought a coffee from Starbucks with no fear of being poisoned or cheated. I caught a train on London’s underground packed with people I’ve never met before and will probably never meet again. If we were commuting chimps in a space that small, it would have been a scene out of the latest Planet of the Apes by the time we reached Holborn station. We’ll return to this mystery in a moment.
There is something very natural about prioritizing your family over other people. There is something very natural about helping your friends and others in your social circle. And there is something very natural about returning favors given to you. These are all smaller scales of cooperation that we share with other animals and that are well described by the math of evolutionary biology. The trouble is that these smaller scales of cooperation can undermine the larger-scale cooperation of modern states. Although corruption is often thought of as a falling from grace, a challenge to the normal functioning state—it’s in the etymology of the word—it’s perhaps better understood as the flip side of cooperation. One scale of cooperation, typically the one that’s smaller and easier to sustain, undermines another.
When a leader gives his daughter a government contract, it’s nepotism. But it’s also cooperation at the level of the family, well explained by inclusive fitness2, undermining cooperation at the level of the state. When a manager gives her friend a job, it’s cronyism. But it’s also cooperation at the level of friends, well explained by reciprocal altruism3, undermining the meritocracy. Bribery is a cooperative act between two people, and so on. It’s no surprise that family-oriented cultures like India and China are also high on corruption, particularly nepotism. Even in the Western world, it’s no surprise that Australia, a country of mates, might be susceptible to cronyism. Or that breaking down kin networks predicts lower corruption and more successful democracies (Akbari, Bahrami-Rad & Kimbrough, 2017; Schulz, 2017). Part of the problem is that these smaller scales of cooperation are easier to sustain and explain than the kind of large-scale anonymous cooperation that we in the Western world have grown accustomed to.
So how is it that some states prevent these smaller scales of cooperation from undermining large-scale anonymous cooperation? The typical answer is that more successful nations have better institutions. All that’s required is the right set of rules to make society function. But even on the face of it, this answer seems incomplete. If it were true, Liberia, who borrowed more than its flag from the United States, ought to be much more successful than it is4. Instead, these institutions are supported by invisible cultural pillars without which the institutions would fail. For example, without a belief in rule of law—that the law applies to all and cannot be changed on the whim of the leader—it doesn’t matter what the constitution or legal code says, no one is listening. Without a long time horizon, decisions are judged on how well they serve our immediate needs making larger-scale projects, like reducing the effects of Climate Change, harder to justify5. Similarly, institutions often lack the punitive power to actually punish perpetrators. For example, most people in the US and UK pay their taxes, even though in reality the IRS and Her Majesty’s Revenue and Customs lack the power to prosecute widespread non-compliance; your probability of getting caught is low. The tax compliant majority may never discover that they can cheat or how to get away with it (Chetty, et al. 2013) and they may not actively seek this information as long as the probability of getting caught is non-zero, the system seems fair, and it seems like everyone else is complying. Or in other words, it’s a combination of norms and institutions. But, it gets tricky—institutions are themselves hardened or codified norms6 and the norms themselves evolve in response to the present environment and due to path-dependence of previous environments, past decisions, and the places migrants come from. Modern groups vary on individualism (Talhelm, et al., 2014) and even sexist attitudes (Alesina, et al., 2013) based on their ancestors’ farming practices7. The science of cultural evolution describes the evolution of these norms and introduces the possibility of out-of-equilibria behavior (people behaving in ways that do not benefit them individually) for long enough for institutions to try to stabilize the new equilibria. For a summary of cultural evolution, see Joseph Henrich’s excellent book and for an even shorter summary see this chapter). How do we begin to understand these processes?
The real world is messy and before we start running randomized control trials or preparing case studies, it’s useful to model the basic dynamics of cooperation using a simpler form that gets at the core elements of the challenge. One commonly used model is called the “Public Goods Game”. The gist of the game is that I give you, and say 9 others, $10. Whatever you put into a pool (the public good), I’ll multiply by say 3, but then I’ll divide the money equally regardless of contribution. This is similar to paying your taxes for public goods that we all benefit from, like roads, clean water, or environmental protections. The dilemma is this: the best move is for everyone to put all their money in the pool. Then they’ll all go home with $30. But it’s in my best interests to put nothing in the pool and let everyone else put their money in. If I put in nothing and they put in $10 each, I’ll go home with almost $40 ($10*9*3people / 10 = $37). What happens when we play this game?
Well, if we play it in a WEIRD8 nation, where prosocial norms tend to be higher, people put about half their money in, but as they gradually realize they can make more by putting in less, contributions dwindle to zero. One way to sustain contributions is to introduce peer punishment—allow people to spend some portion of their money to punish other people. This is similar to the kind of punishment we might see in a small village. I know who you are or at least I know your parents or people you know. If you steal my crops, I’ll punish you myself or ruin your reputation. In the game, if we introduce the possibility of peer punishment, contributions rise again. The problem is that this doesn’t scale well. As the number of people grows, we get second-order free-riding—people prefer to let someone else pay the cost of punishment. When someone cuts a queue, you grumble—someone ought to tell that person off! Someone other than me… And you can also get counter-punishment—revenge for being punished. The best solution seems to be to create a punishment institution. Pick one person as a “Leader” and allow them to extract taxes that can be used to punish free-riders. This works really well and scales up nicely. It’s similar to a functioning police force and judiciary in WEIRD nations. In fact, the models suggest that the more power you give to the leader, the more cooperation they can sustain. Aha! Problem solved. Not quite. Models like these are very useful for distilling the core of a phenomenon, they can miss things. Recall where we started—smaller-scales of cooperation can undermine the larger-scale.
In our recently published paper, we wanted to show just how easy it was to break that well-functioning institution. We did it by introducing the possibility of another very simple form of cooperation—you scratch my back, I’ll scratch yours—bribery. And then we wanted to show the power of invisible cultural pillars by measuring people’s cultural background and by trying to fix corruption using common anti-corruption strategies. We wanted to show that these strategies, including transparency, don’t work in all contexts and can even backfire.
Our “Bribery Game” was the usual institutional punishment public goods game with the punishing leader, but with one additional choice—players could not only keep money for themselves or contribute to the public pool, they could also contribute to the leader. And the leader could not only punish or not punish, they could instead accept that contribution. What happened? On average, we saw contributions fall by 25% compared to the game without bribery as an option. More than double what the pound has fallen against the USD since Brexit (~12%9). Fine, bribery is costly. The World Bank estimates $1 trillion is paid in bribes alone; in Kenya, 8 out of 10 interactions with public officials involves a bribe, and as Manfred Milinski points out in his summary of our paper, most of humanity—6 billion people—live in nations with high levels of corruption. Our model also reveals that unlike the typical institutional punishment public goods game, where stronger institutions mean that more cooperation can be sustained, when bribery is an option, stronger institutions mean more bribery. A small bribe multiplied by the number of players will make you a lot richer than your share of the public good! So can we fix it?
The usual answer is transparency. There are also some interesting approaches, like tying a leader’s salary to the country’s GDP—the Singaporean model10. So what happened when we introduced these strategies? Well, when the public goods multiplier was high (economic potential—potential to make money using legitimate means—was high) or the institution had power to punish, then contributions went up. Not to levels without bribery as an option, but higher. But in poor contexts with weak punishing institutions, transparency had no effect or backfired. As did the Singaporean model11. Why? Consider what transparency does. It tells us what people are doing. But as psychological and cultural evolutionary research reveals, this solves a common knowledge problem and reveals the descriptive norm—what people are doing. For it to have any hope of changing behavior, we need a prescriptive or proscriptive norm against corruption. Without this, transparency just reinforces that everyone is accepting bribes and you’d be a fool not to. People who have lived in corrupt countries will have felt this frustration first hand. There’s a sense that it’s not about bad apples—the society is broken in ways that are sometimes difficult to articulate. But societal norms are not arbitrary. They are adapted to the local environment and influenced by historical contexts. In our experiment, the parameters created the environment. If there really is no easy way to legitimately make money and the state doesn’t have the power to punish free-riders, then bribery really is the right option. So even among Canadians, admittedly some of the nicest people in the world, in these in-game parameters, corruption was difficult to eradicate. When the country is poor and the state has no power, transparency doesn’t tell you not to pay a bribe, it solves a different problem—it tells you the price of the bribe. Not “should I pay”, but “how much”?
There were some other nuances to the experiment that deserve follow up. If we had played the game in Cameroon instead of Canada, we suspect baseline bribery would have been higher. Indeed, people with direct exposure to corruption norms encouraged more corruption in the game controlling for ethnic background. And those with an ethnic background that included more corrupt countries, but without direct exposure were actually better cooperators than the 3rd generation+ Canadians. These results may reveal some of the effects of migration and historical path dependence. Of course, great caution is required in applying these results to the messiness of the real world. We hope to further investigate these cultural patterns in future work. The experiment also reveals that corruption may be quite high in developed countries, but its costs aren’t as easily felt. Leaders in richer nations like the United States may accept “bribes” in the form of lobbying or campaign funding and these may indeed be costly for the efficiency of the economy, but it may be the difference between a city building 25 or 20 schools. In a poor country similar corruption may be the difference between a city building 3 or 1 school. Five is more than 3, but 3 is three times more than 1. In a rich nation, the cost of corruption may be larger in absolute value, but in a poorer nation, it may be larger in relative value and felt more acutely.
The take home is that cooperation and corruption are two sides of the same coin; different scales of cooperation competing. This approach gives us a powerful theoretical and empirical toolkit for developing a framework for understanding corruption, why some states succeed and others fail, why some oscillate, and the triggers that may lead to failed states succeeding and successful states failing. Our cultural evolutionary biases lead us to look for whom to learn from and perhaps whom to avoid. They lead us to blame individuals for corruption. But just as atrocities are the acts of many humans cooperating toward an evil end, corruption is a feature of a society not individuals. Indeed, corruption is arguably easier to understand than my fearless acceptance of my anonymous barista’s coffee. Our tendency to favor those who share copies of our genes—a tendency all animals share—lead to both love of family and nepotism. Putting our buddies before others is as ancient as our species, but it creates inefficiencies in a meritocracy. Innovations are often the result of applying well-established approaches in one area to the problems of another. We hope the science of cooperation and cultural evolution will give us new tools in combating corruption.
1 Putting aside what it means for something to be natural for our species, suffice to say these are recent inventions in our evolutionary history, by no means culturally universal, and not shared by our closest cousins.
2 Genes that identify and favor copies of themselves will spread.
4 The United Nations Human Development Index ranks the United States 10th in the world. Liberia is 177th.
5Temporal discounting the degree to which we value the future less than the present. Our tendency to value the present over the future is one reason we don’t yet have Moon or Mars colonies, but the degree to which we do this varies from society to society.
6 Written laws can serve a signaling and coordination function; rather than having to interpret norms from the environment. When previously contentious norms are sufficiently well established, you may do well to codify them in law (legislating before they are established might mean more punishment—consider the history of prohibition in the United States).
7 Not that agriculture is the main reason for these cultural differences!
10 Singapore’s leaders are the highest paid in the world, but the nation also has one of the lowest corruption rates in the world—lower than the Netherlands, Canada, Germany, UK, Australia, and United States [source].
11 Note, there are some conceptual issues that make interpretation of the Singaporean treatment ambiguous. We discuss this in the supplementary. We’ll have to further explore this in a future study. Such is science.
Ted Slingerland and I were awarded a Templeton Foundation grant for “The Database of Religious History: A Digital Humanities Approach to Religious
Cultural History” ($2,342,841). The grant will take us through to 2020, by which time we hope to have set up the project as a foundation.
If you’re a historian, please let us know if you would like to contribute. For everyone else, I encourage you to browse through our data: http://religiondatabase.org/browse/landing/
I was recently interviewed by Focus Magazine, a popular magazine in the Russian-speaking world. It was a wide-ranging interview, where we discussed my research on cultural evolution and the implications for some of the events taking place in the world today, including the Migration Crisis, climate change, and the rise of populist politicians.
I gave a keynote presentation at the Lorentz Center conference on “Trusting and the Law“. This was my first legal conference. The audience included judges, lawyers, and legal scholars. I presented a talk on “Economic Psychology and the Science of Cultural Evolution”, where I discussed some of the “invisible cultural pillars” that uphold legal institutions. It was fascinating to discuss differences in the approach to “evidence” in science and the law.
I was invited to present my work on innovation and cultural evolution at the “Cultural Transmission and Social Norms Workshop” hosted by the School of Economics at The University of East Anglia, UK. I presented “Innovation in the Collective Brain: The Transmission and Evolution of Norms and Culture”, beginning with an introduction to cultural evolution for the audience of primarily economists. I then discussed innovation as a product of our “collective brains“.
I was recently awarded an 18 month grant (with Co-PI Ted Slingerland) for “The Database of Religious History: Data Science Approaches to Religious Cultural History” ($215, 050). The grant will enable us to continue a critical period in the project’s development. We are hoping to secure additional funds to ensure a self-sustaining future for the project.
Part of this period was improving the data entry and browsing interface. If you’re a historian, please let us know if you would like to contribute. For everyone else, I encourage you to browse through our data: http://religiondatabase.org/browse/landing/
