Character and their quality.
What makes people different from each other?
DNA makes the first impact.
The location we born and grow up makes the second impact.
Our surrounding people and environment during our childhood makes the third impact.
The rest of our existence goes by our individual senses and how we pick up our path. Which many behaviors unfolds under categories such as traits and characteristics.
The way our mind works.
Forget about different circumstances. Identical twins raised together will have much in common because of their upbringing and education yet they will still be individuals, differing from each other. Their minds interpret things differently so their personality develops as uniquely their own.
And as for triplets, that famous 20th century psychologist, Danny Kaye, had the defining comment.
Well you can start with genetics.
Our DNA is different since we each carry forth good and bad traits (mutations) from our parents whom carried them forth from their parents.
Then the environment we grew up in in regards to what we ate, drank, the gases and light elements we were exposed to . . . These all contributed to our brain development and physiology.
Next comes the experiences we had growing up . . . The traumas or the delights, that caused our neural net to grow this way and that.
Those three elements contribute to the person each of us are to this day . . . And they will continue to be contributors to who are until we die.
personality.
