The platysma changes the facial expression which plays an important role in human social behavior. In elderly people â when the skin increasingly loses its elasticity â both inner faces of the platysma form two longitudinal wrinkles on the neck.
Biological psychology is a branch of psychology that studies the physiological causes of behavior. This field is sometimes referred to as behavioral neuroscience or biopsychology.
Personality can be defined as a set of characteristics or traits that drive individual differences in human behavior. From a biological perspective, these traits can be traced back to brain structures and neural mechanisms. However, this definition and theory of biological basis is not universally accepted. There are many conflicting theories of personality in the fields of psychology, psychiatry, philosophy, and neuroscience.