1) All behavior has a physiological basis:
This can be seen in the case studies of Phineas Gage who was a railroad worker who suffered a personality change after an iron rod shot through his brain. Damasio et al (1994) used imaging techniques to reconstruct the exact path of the iron rod. They were able to create a three-dimensional model of Gage's skull that showed that the iron bar went through prefrontal areas of the brain, thus showing a link between a specific part of the brain and social and emotional reasoning.
2. Behavior can be inherited.
One of most well known and largest studies into twins is the Minnesota Twin Study ( Bouchard et al, 1990), a longitudinal study that has been ongoing since 1979, conducted at the University of Minnesota.The study tracks down separated twins from across the world and participants complete approximately 50 hours of medical and psychological assessments including personality traits,
occupational interests and mental ability. He found that an identical twin reared away from his or her cotwin seems to have about an equal chance of being similar to the co-twin in terms of personality,interests, and attitudes as one who has been reared with his or her co-twin. This leads to the conclusion that the similarities between twins are due to genes, not environment, since the differences between twins reared apart must mainly be due to the environment.
3. Behaviour may be influenced by evolutionary processes.
For example, a study by Chartrand & Bargh (1999 ) examined the chameleon effect in humans. The chameleon effect is the natural tendency to imitate each other's each other's body postures, hand gestures, speaking accents, and other behaviours. Their study showed that people who engaged in more imitative behavior rated the person they imitated higher in terms of likeability, suggesting that mimicry (imitation) facilitated social interaction and bonding, an important adaptive behavior for the success of the group.
4. Animal studies provide insight into human behaviour.
Experiments on animals have made an important contribution to advances in medicine and psychology that have brought major improvements in the health and well being of humans and animals. Studies that we look at (have looked at) using animals include;Martinez & Kesner ( 1991 ) the role of acetycholine on memory (rats) Rosenzweig and Bennett (1972 ) effects of deprivation on brain development (rats)Matsuzawa (2007) Spatial memory (chimpanzees)Zola-Morgan et al (2000) Hippocampal damage and memory ( monkeys)Harlow (1962) Love in infant monkeys. However the use of animals in psychological research raises huge ethical issues about the use and treatment of animals in research.