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Unlock This CourseWhy do humans help each other? Why do we feel good when we donate to charity or help a stranger? Biological explanations suggest that our tendency to help others isn't just learned behaviour - it's actually built into our genes, brains and biology. This approach argues that prosocial behaviour has evolved because it helps our species survive and thrive.
Key Definitions:
Humans who helped each other were more likely to survive harsh conditions, find food and protect their children. Over thousands of years, this meant that people with 'helping genes' were more successful at passing on their DNA to the next generation.
The strongest biological argument for prosocial behaviour comes from evolutionary theory. Scientists argue that helping others actually helps us survive as a species, even if it sometimes costs us individually.
This theory suggests we're more likely to help people who share our genes - our family members. The closer the genetic relationship, the more likely we are to help. This makes evolutionary sense because when we help our relatives survive, we're helping our own genes continue into the future.
Share 50% of genes. Parents will sacrifice almost anything for their children's survival.
Share 50% of genes. Brothers and sisters often help each other throughout life.
Share 12.5% of genes. Less likely to help, but still more than strangers.
Biologist William Hamilton created a mathematical formula: rB > C. This means we'll help others when the benefit (B) to our relative, multiplied by how closely related we are (r), is greater than the cost to ourselves (C). For example, you might risk your life to save two siblings or eight cousins, because the genetic benefit outweighs the personal cost.
But humans don't just help family members - we also help strangers. Evolutionary psychologists explain this through reciprocal altruism: "I'll help you now and you might help me later." This creates a network of mutual support that benefits everyone's survival.
Research shows that the most successful strategy in repeated interactions is to start by cooperating, then copy what the other person does. If they help you, you help them back. If they don't help, you stop helping them. This encourages a culture of mutual assistance.
Modern brain scanning technology has revealed fascinating evidence that our brains are literally wired for helping others. Several key brain areas and systems support prosocial behaviour.
These special brain cells fire both when we perform an action and when we watch someone else perform the same action. They help us understand and empathise with others' experiences, making us more likely to help when we see someone in distress.
Brain imaging studies show that when we see someone in pain, several areas of our own brain become active - almost as if we're experiencing their pain ourselves. This includes the anterior cingulate cortex and the anterior insula, which are involved in processing our own emotional experiences.
Processes emotional pain and distress, both our own and others'.
Helps us understand and share others' emotional states.
Plans and executes helping behaviour based on empathetic responses.
Our hormones also play a crucial role in prosocial behaviour. Several key hormones have been linked to increased helping, bonding and cooperation.
Often called the "love hormone," oxytocin is released during physical contact, childbirth and social bonding. Studies show that people with higher oxytocin levels are more generous, trustworthy and likely to help others.
Researchers gave participants either oxytocin or a placebo through a nasal spray. Those who received oxytocin donated significantly more money to charity and were more likely to help strangers with tasks. They also showed increased activity in brain areas associated with empathy and social bonding.
This hormone promotes bonding and protective behaviour, especially in males. It's linked to increased aggression towards threats to loved ones and stronger motivation to help family members.
Some of the strongest evidence for biological influences on prosocial behaviour comes from twin studies. By comparing identical twins (who share 100% of their genes) with fraternal twins (who share 50% of their genes), researchers can estimate how much of our helping behaviour is inherited.
Studies consistently show that identical twins are more similar in their prosocial behaviour than fraternal twins, even when raised in different families. This suggests that genetics account for approximately 40-60% of individual differences in helping behaviour.
This famous long-term study followed twins separated at birth and raised in different families. Researchers found that identical twins showed remarkably similar patterns of charitable giving, volunteering and helping behaviour, despite growing up in completely different environments. This provides strong evidence for genetic influences on prosocial behaviour.
Biological explanations also help us understand why helping others feels so good. When we help someone, our brains release endorphins and dopamine - the same chemicals involved in other pleasurable experiences like eating chocolate or falling in love.
Brain scans show that giving money to charity activates the same reward centres as receiving money for yourself. This suggests that evolution has made helping others inherently rewarding to encourage prosocial behaviour.
Research with very young children provides additional support for biological explanations. Babies as young as 6 months old show preferences for helpful characters over harmful ones, suggesting that prosocial tendencies emerge before extensive social learning has occurred.
Experiments show that 14-month-old toddlers will spontaneously help adults who are struggling with tasks, even without being asked or rewarded. This early emergence of helping behaviour suggests it may be biologically programmed rather than purely learned.
Researchers showed 6-month-old babies puppet shows where one character helped another climb a hill, while a second character pushed them down. When given the choice, babies overwhelmingly preferred to play with the helpful puppet. This suggests that even before they can walk or talk, humans have an innate preference for prosocial behaviour.
If prosocial behaviour is truly biological, we should see similar patterns across different cultures. Research supports this, showing that while the specific forms of helping vary between cultures, the underlying tendency to help others is universal.
Every known human culture has norms about helping others, sharing resources and caring for the vulnerable. This universality suggests biological rather than purely cultural origins.
The biological explanation for prosocial behaviour presents compelling evidence that our tendency to help others is deeply rooted in our genes, brains and evolutionary history. From the genetic advantages of kin selection to the neurochemical rewards of helping, biology provides a comprehensive framework for understanding why humans are fundamentally prosocial creatures. While environmental factors certainly influence how and when we help others, the biological foundation appears to be universal and fundamental to human nature.