Chapter 13: development of the self and social cognition. Self: the combination of physical and psychological attributes that is unique to each individual. Social cognition: thinking that people display about the thoughts, feelings, motives, and behaviors of themselves and other people. Proprioceptive feedback: sensory information from the muscles, tendons, and joints that helps us locate the position of our body (or body parts) in space. Most developmentalist believe that infants come to distinguish themselves from the external environment over the first 2 to 6 months of life. Personal agency: recognition that one can be the cause of an event (2 month old limited sense of personal agency or responsible for at least 1 event) Self concept: one"s perceptions of one"s unique attributes or traits. Present self: early self-representation in which 2 and 3 years olds recognize current representations of self but are unaware that past self-representations or self-relevant events have implications for the present.