When psychologists talk about personality, they are concerned primarily with individuals difference the characteristics that distinguish one individual from another personality can be defined as the characteristics patterns of behaviour and modes of thinking that determine a person’s adjustment to the environment.

An infant is born with certain potentialities. The development of these potentialities depends upon I maturation and upon experiences encountered in growing up. Although newborn infants in a hospital nursery look pretty much alike, the physical characteristics that will later make them readily distinguishable from each other are already determined by heredity.

Intelligence and certain special abilities, such as musical talent, also have a large hereditary component, and some differences ii emotional reactivity may be innate individual differences could be observed shortly after birth in such characteristics as activity level, attention span, adaptability to changes in the environment, and general mood.