What causes different outcomes, traits, personalities or temperaments of two people with the same social background? Why does my personality differ from my brother/sister’s if we were born to the same parents, lived in the same neighbourhood, went to the same elementary and high school?
Personality is generally described as a characteristic way of thinking, feeling, understanding and behaving. It includes moods, tendencies, attitudes, opinions and beliefs and is most visible in our interactions with other people and our environment. It encompasses behavioural traits, both inherent and acquired, that differentiate one person from another.
It is something that comes from within, something inherent to a person, something that establishes a cause-effect (causal) relationship to our choices, ambitions, inclinations and reactions when we come up against a particular situation/s.
Human personalities are somewhat like fractals – infinitely complex structures and patterns that are self-similar and remain invariant in different scales. They are made by recursive processes – processes which refer to themselves in a continuous feedback loop.
It is not just the big things and choices we make in our lives – like relationships or career – that tend to be pretty consistent over time (with us frequently repeating the same mistakes or triumphs), but also the tiny things – the way we dress, talk to strangers or do our shopping – that show the same patterns. We can also often predict the behaviours of others and describe them as typical for that individual – having in mind the set of situations we have already seen them in.

Just as the self-similar properties of fractals are made by the mathematical functions that define them, so are the self-consistent properties of personalities generated by some physical properties of our nervous systems.
There are several wide-ranging personality dimensions along which we all differ, and which lead us to behaving in certain ways. A majority of what happens in our careers, friendships, love and health come from where we land along these continua. The way our brains are wired up and its determinants (genetics and different early life influences) decide where we will eventually land. Does this mean that personality is unchangeable? And what is the ideal personality to have?
The truth is that by merely understanding the process in which our personalities are built will already have an influence on it and might make us choose different options in our future interactions and choices, and by doing so provide with an alternative feedback for our personality-creating loop.
Furthermore, there is no ideal personality to have. Every dimension brings both advantages and disadvantages. You shouldn’t feel bad about your level of any singular trait, but rather focus on its benefits.
Try to organize your life in a way which allows you to show off your strengths and protect yourself and work on the areas you’re weak in. Although it may sound apparent, most people take a long time to figure out what their true strengths and weaknesses are, to put in proportion what you (and the people around you) wish you were like and what you actually are like.
Personality traits can be manifested in many ways and if they are worrying or bothering you, you should try to find alternative, less destructive outlets for the same traits. You are not changing yourself, just your personality’s outlets.
[1] Nettle, D. (2009). Personality: What Makes You the Way You Are. Oxford: Oxford University Press.