Although they share the same genes and grow up in the same environment, identical twins develop different personalities and behave in increasingly different ways as they get older. Scientists at the Salk Institute in La Jolla, California, have conducted experiments on mice to find out if these differences are reflected in the brain. And they have concluded that the time each twin spends exploring the environment throughout their lives translates into significant differences in the number of neurons contained in their hippocampus, an area of the brain involved in learning and memory. .
These differences increase as the subjects age, in such a way that those who in their individual experiences have more activity in exploring the environment generate three times as many neurons in the hippocampus. And that causes their personalities, behavior patterns and preferences to diverge , according to the authors of the research in the journal Science . In addition, as their behavior changes, the way they use and function in the environment also changes, encouraging each one to develop a unique personality.
That exercise stimulates neurogenesis was already known to scientists, but this is the first time that research has linked the birth of new neurons and the evolution of the brain with the intensity with which an individual explores the environment . In other words, the way we live, the small choices and daily experiences, determine how we are and change our "plastic brain".
