Nature vs. Nurture

Genetics  All creatures have a unique genetic code, or biological blueprint That blueprint is found inside every cell in the body Inside each cell nucleus are chromosomes that are composed of DNA Humans have about 30,000 genes

Nature  Human Similarities All humans share 99.9%of the same DNA sequence Evolutionary psychologists believe that some of our similarities stem from mutated genes Natural selection says that traits that aid our survival are most likely to passed down among generations  Individual Differences Behavior geneticists study individual differences using twin studies and adoption studies

Nature  Twin studies Identical twins are genetically the same because they come from the same fertilized egg

Nature  Twin studies Fraternal twins develop from two different fertilized eggs

Nature  Twin studies Behavior geneticists study the similarities that exists between sets of twins in many areas– genetics, personality traits, and shared behaviors

Nature  Twin studies have helped teach us a lot about inherited traits  Studies of identical twins separated at birth have demonstrated that no trait is completely inherited and that the behavior of identical twins isn’t necessarily identical.  Psychologists have studied separated identical twins and found similarities in heart rate, brain waves, intelligence level, personalities, abilities, attitudes, and fears

Adoption Studies  Adoption studies have shown that adopted children share more personality trait similarities with their biological parents than they do with their adoptive parents  Studies have also shown that parenting plays the largest role in development of belief systems and social functioning behaviors

Environmental Factors  Three main factors account for nurture’s role in personality development Early learning experiences Peer influence culture

Environmental Factors  Early Learning and Brain Development The brain processes we use in early learning pave the way for learning more complex information later. ○ For our brain to meet their developmental potential, early experience is critical The brain’s pathways that we maintain through regular use will continue to get stronger, while neglected pathways will fade with disuse.

Environmental Factors  Culture The shared attitudes, beliefs, norms and behaviors a group communicates from one generation to the next. ○ Culture influences our food selection, religious choices, family activities, and more Because of our cultural rules we develop a set of expectations about the kinds of behaviors others should exhibit