Differences in human personality have long been a subject of debate: just one aspect of this is our varying needs for human connection. Experts with a Graduate Diploma of Psychology are well aware of the ways affiliation is a core aspect of human psychology, but despite being essential in some capacity, we all have different needs. The human brain is a vast and complex mystery that we have only just begun to unravel, and even cutting-edge neuroscience often fails to provide a first principles account for much of what we experience in ourselves and observe in others. One trait, known as extroversion, or need for affiliation, has been studied extensively, and is one of the few personality traits that we actually understand quite well.
What is affiliation?
One of the traits that varies most dramatically on an individual basis is our propensity to socialise, also known as our need for affiliation. While most people have a strong need for affiliation, and a corresponding drive to socialise regularly, others experience very little desire for personal connection, and prefer to keep to themselves. In the field of personality psychology, these tendencies are often referred to as extroversion and introversion, respectively. These traits can vary to quite irregular extremes: while the most extroverted among us truly crave connection and feel a need to be around others nearly at all times, others with a naturally introverted disposition rarely, if ever, socialise willingly, and can even see being around others as a source of stress.
The terms introversion and extroversion were coined by Carl Jung, a pupil of Sigmund Freud who developed an extensive theoretical framework that attempted to explain what he observed as the different dimensions of human personality.
What is the evolutionary basis of affiliation?
Unlike many apex predators that come to dominate their environments, humans have been so evolutionarily successful in large part due to our inherently social natures and tendency to collaborate in large groups. This trait is more common in herbivorous prey animals, but in general, most animals tend to engage in at least limited social behaviours, as interaction with others of the same species is always necessary, at a minimum, for procreation. But unlike other animals, humans derive more complex benefits from socialisation, largely as a result of our highly evolved and nuanced communication skills. Humans have survived and flourished largely as a result of our ability to pass down knowledge from generation to generation, whether that be which red berries we can eat, or how to manufacture the advanced farming equipment that allows us to persist in incredible numbers across an often hostile planet.
The psychological benefits of affiliation
It’s undeniable that, for the vast majority of people, affiliation and regular socialisation has a net positive psychological impact. This is especially important for younger people, whose early socialisation is vital for teaching them prosocial behaviour. But adults require affiliation, too, and those who do not interact with others often report being less happy. Indeed, some studies have shown that a failure to socialise often has deeply negative physical impacts on people.
Why some need less affiliation than others
Oddly enough, this is one personality trait that we understand rather well from a neurobiological standpoint. Introverts are generally agreed to have what is known as a lower threshold for arousal. This means that introverts are more easily stimulated by external stimuli and, as a result, become over-stimulated more easily. Studies have shown that this is likely the result of introverts having a higher sensitivity to dopamine, a neurotransmitter that the brain uses as a method of rewarding and reinforcing certain behaviours. Extroverts, on the other hand, are less sensitive to dopamine, and as a result they both require more stimulation in order to feel the dopamine reward, and are also less easily over-stimulated. This biological mechanism for personality traits was first elucidated in a very generalised manner by British-German psychologist Hans Eysenck back in 1967, who further elaborated his theory about introverts being more sensitive to external stimuli in 1981. Subsequent studies have validated Eysenck’s predictions, with others exploring the difference in the structure of the brains of introverts and extroverts. Some studies even go so far as to tie the trait to specific genes relating to dopamine transmission and re-uptake rates.
The more we uncover about the human brain, the more we may be tempted to see ourselves as nothing more than fleshy automata following the instructions written into our genes as they emerge in our individual psyche as ephemeral impulses — mere biological programming set in place by evolution to fulfil the base function of survival and reproduction. But the truth is, we are so much more than our genes — indeed, there is an entire field of study called epigenetics that seeks to explain, for example, why even identical twins with mirrored genomes can sometimes look and behave quite differently as a result of their environmental influences. In truth, the great mystery of human psychology will remain for some time to come as just that — an intricate riddle, with fresh mysteries aplenty to solve for the next generation of ambitious scientists, researchers, and inquiring minds.