Do Monkeys Have a Moral Compass?

Studies have suggested babies as young as fifteen months can work out when food distribution is unfair and takes steps to correct this imbalance demonstrating how fairness sensitivity emerges early in human development before language or explicit moral instruction representing innate capacity for distributive justice where pre-verbal infants detect inequitable resource allocation and actively intervene to restore balance suggesting fairness concerns are foundational to human moral psychology rather than culturally learned showing proto-moral sensibilities present before socialization.

Brown capuchin monkeys were tested to see how cooperative they would be in task if they found out they would not always be fairly compensated where monkeys asked to give human testers token in exchange received treat some monkeys received piece of cucumber while others received grape the grape being much tastier treat demonstrating how fairness perception emerges through social comparison where inequity aversion manifests when individual receives inferior reward for identical effort representing evolutionary foundation for distributive justice sense through comparative evaluation driving cooperation withdrawal when social contract violated suggesting proto-moral sensitivity to proportional compensation.

In another experiment also with capuchin monkeys test subjects were put into pairs and one of each pair was offered choice of two tokens where selfish token gave them access to slice of apple but meant partner got nothing while helpful token meant both monkeys got treat demonstrating how prosocial preference emerges when cost to self is zero with monkeys choosing helpful token more often showing they didn’t see any reason not to secure friend treat representing other-regarding preferences but changed depending on how well monkeys got to know each other where familiarity increased prosocial behavior suggesting empathic motivation scales with social bonding strength.

Male chimpanzees were tested with ultimatum game where one chimp offered split of food to partner and partner could accept or reject offer where if offer rejected neither chimp received any food demonstrating how spiteful punishment emerges where male chimps more likely than females to reject unfair offers even though rejection meant they also got nothing representing costly punishment of inequity violation suggesting spite has evolutionary function in enforcing fairness norms where willingness to pay cost to punish defectors maintains cooperative equilibrium through credible threat of sanction even when punishment hurts punisher showing second-order fairness enforcement mechanism.

Monkeys have been seen to make up after fights and in fact making friends after bust up leaves them feeling better about themselves where when monkeys reconcile after fights they feel better demonstrating how conflict resolution reduces physiological stress where indicators for distress and anxiety like elevated heart rate and compulsive scratching decrease representing social repair mechanism with measurable health benefits suggesting forgiveness capacity in primates evolved to restore social bonds after aggression maintaining group cohesion through active reconciliation behaviors that alleviate stress response.

We do have evidence that apes and some monkeys have sense of self where mirror or mark test is established test that tries to prove if animal is self-aware that it knows it exists as individual where animal has dot painted or laser pointed on part of body they can’t see with own eyes and placed in front of mirror demonstrating how self-recognition capacity distinguishes species where animals that don’t have sense of self can’t understand creature in mirror is doing exactly what they do therefore must be themselves while animals that do recognize mirror creature performing same actions will try to touch painted dot on own head with most animals and kids under two can’t pass test but some monkeys can where one study demonstrated with laser pointer monkey always touched dot on head and notably such monkeys with mirrors constantly use mirrors to inspect own butt showing self-awareness enables body inspection.

Study done on Japanese macaques suggested they might have theory of mind where scientists used established experiment usually used on human children called false belief task where monkeys shown video of person A placing object in box A then person A leaves room and person B moves object to box B without person A seeing demonstrating how mentalizing capacity measured through false belief understanding where scientists then measure where monkeys looked when person A returns to room to gauge if they would expect person A to look in box A or box B representing perspective-taking test where monkeys looked to original location suggesting they understood person A would not know object had been moved that is they understood person A had their own set of beliefs and view of world separate to person B and separate to themselves showing theory of mind but similar study done on rhesus macaques was less successful so it likely differs in different species.

Some researchers suggest that monkeys understand that other monkeys see hear and know different things than them but they probably don’t understand that other monkeys have different beliefs about world demonstrating how mentalizing hierarchies distinguish perceptual state attribution from belief state attribution where monkeys capable of first-order perspective-taking regarding sensory access but lack second-order representational understanding of belief content representing cognitive limitation where understanding others have different perceptual experiences doesn’t require understanding others hold different propositional attitudes about reality showing graded theory of mind capacity with perceptual level accessible but belief level unavailable to most monkeys.

We know that moral behavior in humans can be linked to certain parts of brain and to certain hormones that modulate brain activity where study of morality and brain has been coined neuromorality and is in its infancy in science terms demonstrating how moral judgment emerges from neural substrate where it often involves asking test subjects to carry out certain actions or watch videos or respond to stimulus while having brain activity monitored representing neuroscientific approach to ethics where we can see from these studies that certain neural networks are associated with assessing intentions of others and that these networks can interact to make judgment about where blame lies for certain actions showing distributed processing with intention assessment networks feeding into blame attribution circuits revealing computational architecture of moral cognition.

We’ve also seen that serotonin can enhance negative feelings when we observe others enduring harm making us more likely to be empathetic demonstrating how neurotransmitter systems modulate prosocial motivation where put simply our brains tell us when we see something wrong and we don’t like how that feels representing affective basis of moral behavior where this could help motivate our pro-social actions showing neurochemical mechanism by which vicarious distress drives helping behavior with serotonin amplifying negative emotional response to observed suffering creating aversive state that promotes intervention to alleviate other’s pain.

We can even see differences in how brain responds to moral scenarios in people diagnosed with psychopathy where psychopaths show reduced emotional responses when observing others in distress or pain demonstrating how neurobiological variation underlies individual differences in moral capacity where psychopaths exhibit blunted activity in regions associated with empathy and emotional processing representing dysfunction in affective components of moral cognition with intact cognitive understanding but absent emotional engagement suggesting morality requires both cognitive and affective neural systems where psychopathy shows what happens when affective moral circuitry fails while cognitive capacities remain.

Oxytocin has been shown to increase prosocial behaviors like generosity demonstrating how neuropeptide systems regulate affiliative tendencies where oxytocin often called trust hormone or bonding hormone promotes social bonding trust and cooperation representing neurochemical foundation of prosocial motivation with administration studies showing increased generosity in economic games enhanced cooperation in social dilemmas and greater trust in interaction partners suggesting oxytocin evolved to facilitate group cohesion through chemically-mediated increase in other-regarding preferences.