Hidden Brain: Laurie Talks Monkeys and Bad Money Decisions.
Dr. Laurie Santos, a Yale University psychologist, discusses her research on rhesus and capuchin monkeys with Shankar Vedantam. They explore how monkey behavior reveals the evolutionary origins of human economic biases, like loss aversion and the endowment effect, and highlights unique human cognitive traits.
Deep Dive Analysis
14 Topic Outline
Introduction to Animal Cognition and Human Similarities
Studying Rhesus Monkeys on Cayo Santiago
Monkey Theft and Rational Crime Behavior
Monkeys' Basic Math and Perspective-Taking Abilities
Establishing a Monkey Marketplace with Capuchins
Monkeys' Rational Shopping and Economic Decisions
Loss Aversion and Risk-Taking in Monkeys
The Endowment Effect in Monkeys
Evolutionary Origins of Economic Biases
Inequality and Fairness Perception in Monkeys
Human Impulse to Share and Over-imitation
Human Ability to Understand False Beliefs vs. Monkeys
Price Perception Differences Between Humans and Monkeys
The Dual Nature of Unique Human Cognition
7 Key Concepts
Rational Model of Crime (Monkeys)
Monkeys demonstrate a rational model of crime by selectively stealing from individuals who cannot see them, indicating they calculate the likelihood of detection. This behavior was observed even on the first trial of an experiment.
Understanding Others' Perspectives (Monkeys)
Non-human primates, contrary to earlier beliefs, are good at understanding what others perceive, hear, and know. Experiments show monkeys expect a person to reach for an object where they know it to be, similar to human infants.
Monkey Marketplace
A research setup where capuchin monkeys were taught to use metal tokens as currency to 'pay' human experimenters for different food items. This allowed researchers to study their economic decision-making strategies.
Loss Aversion (Monkeys)
Monkeys, like humans, tend to avoid options framed as losses, even when the objective outcome is the same as a gain. They switch their choice about risk depending on how a problem is arbitrarily framed, taking safe options for gains and risky options for losses.
Endowment Effect (Monkeys)
A bias where individuals overvalue things they own. Capuchin monkeys exhibited this by being unwilling to trade a food item they were 'endowed' with for an equivalent, or even significantly more valuable, food item.
Over-imitation
The human tendency to imitate too much, even copying actions that are obviously unnecessary or inefficient when learning a task. Chimpanzees, in contrast, are more rational and ignore irrelevant actions when the solution is clear.
False Belief Understanding
The human ability to understand that another person can hold a belief that is different from reality or from one's own knowledge. Monkeys can recognize that another person's perspective is different but struggle to simulate the specific content of that false belief.
11 Questions Answered
Studying non-human primates helps distinguish between aspects of the human mind that are products of nurture (culture, teaching) and those that are products of nature (innate capacities), by observing behaviors in the absence of complex human cultural learning.
Yes, studies with rhesus monkeys show they expect the outcome of one plus one to be exactly two, similar to human infants, suggesting this basic math ability is potentially programmed into the brain and doesn't require formal schooling.
Yes, non-human primates are good at understanding what others perceive, hear, and know. Experiments show they predict a person will reach for an object where that person knows it to be.
Yes, capuchin monkeys quickly learned to use metal tokens as currency, exchanging them for food. They demonstrated rational shopping behavior, maximizing their 'food dollar' and preferring foods they liked better.
Yes, monkeys show biases like loss aversion and the endowment effect, reacting to gains and losses and overvaluing what they own, similar to human behavior in economic decision-making.
These biases, though seemingly irrational in modern markets, might have been useful in our evolutionary past by motivating individuals to compare against others and avoid falling below a reference point, aiding in foraging and resource acquisition.
Yes, monkeys pay close attention to what other monkeys have and will reject an offer if they perceive they are getting a 'raw deal' compared to another monkey, even if it means reducing their own resources.
Humans have a fundamental, unique urge to share experiences, feelings, and perspectives with others, which emerges in infancy. Animals, including primates, do not typically show this active desire to share or teach.
Yes, human children tend to slavishly copy all actions shown by an experimenter, even obviously unnecessary ones, when solving a puzzle box. Chimpanzees, however, are more rational and ignore irrelevant actions.
Monkeys can recognize that another person's perspective is different from their own, but they struggle to simulate the specific content of a false belief. They know someone doesn't know what they know, but can't represent what that person *does* believe if it's untrue of reality.
No, this is a key difference. While humans often assume higher-priced items are more valuable or taste better, monkeys in experiments did not fall prey to this bias, showing no preference for 'higher-priced' foods when offered for free.
13 Actionable Insights
1. Overcome Loss Aversion Bias
Recognize and counteract the bias of loss aversion, where you avoid options framed as losses even if the objective outcome is the same as a gain. This bias can lead to irrational choices, such as switching your risk preference based on arbitrary framing.
2. Challenge Endowment Effect
Recognize the endowment effect, a bias where you overvalue things you own. This can prevent rational exchange and lead to holding onto items even when offered objectively more valuable alternatives.
3. Question Price-Value Link
Challenge the common human bias that more expensive things are inherently better; evaluate products based on their objective value and quality rather than price alone, as perceived price can irrationally influence your subjective experience and even brain’s reward areas.
4. Guard Against Over-Imitation
Guard against ‘over-imitation,’ especially when learning from others, as slavishly copying actions (even inefficient or unnecessary ones) can prevent you from finding simpler or better solutions and limit your own exploration.
5. Critically Evaluate Information
Actively develop mechanisms to critically evaluate information received from other humans, as our natural inclination, stemming from our strong sharing impulse, is to over-believe and accept information without sufficient scrutiny.
6. Cultivate Theory of Mind
Cultivate the uniquely human ability not just to recognize that others have different perspectives, but to actively simulate what those specific beliefs are, even if they are false. This deeper understanding is crucial for empathy, social interaction, and comprehending complex narratives.
7. Understand Behavioral Quirks
Seek to understand your own behavioral quirks and cognitive biases, as revealed by comparative studies with animals, to make better, more rational decisions in various aspects of life, especially economic ones.
8. Recognize Ancient Decision Strategies
Understand that many of our economic decision-making strategies are ancient, evolved mechanisms for foraging and survival, not solely for modern money use. Be aware that these strategies, while potentially useful in evolutionary contexts, can lead to ‘quirky’ or irrational behavior in modern complex systems like stock markets.
9. Shop Rationally
Shop rationally by maximizing value (e.g., buying more food for the same price) and consistently choosing preferred items, as even monkeys demonstrate this basic economic rationality.
10. Be Aware of Unfairness Bias
Be aware that the perception of unfairness (getting a ‘raw deal’ compared to others) can lead to rejecting offers, even if it means reducing your own resources, highlighting a deep-seated social comparison mechanism.
11. Cultivate Sharing Impulse
Cultivate the uniquely human impulse to share your thoughts, feelings, and perspectives with others, as this is a fundamental aspect of human connection, learning, and the development of complex culture.
12. Study Infants for Innate Capacities
Study human infants to understand innate cognitive capacities (e.g., basic math skills) that exist without much experience or formal training, providing insight into the ’nature’ aspect of human cognition.
13. Understand Social Structure for Economy
Understand that a relatively egalitarian social structure is necessary for a species to effectively use a money-based economy, as strict dominance hierarchies can undermine individual wealth and rational exchange.
6 Key Quotes
If you're really looking for the pure things that the human mind has in the absence of those different processes, it's not great to study adult humans.
Laurie Santos
It's kind of sad to admit that you're getting ripped off by monkeys, but it happens more than you'd think on the island.
Laurie Santos
Humans are amazing species, but, you know, pick up any article of The Economist and you figure out that we're not great at money.
Laurie Santos
I think even if animals had photographs, they wouldn't use them. You know, if they had their iPhone 11, they wouldn't take pictures.
Laurie Santos
We don't have mechanisms to be critical about the things we're hearing from other humans.
Laurie Santos
It's remarkable that the very things that make us so special and so smart can also, in some context, make us seem kind of dumb.
Laurie Santos