PSYC 2P25 Lecture Notes - Lecture 1: Probability Distribution, Nomothetic, Physical Attractiveness
Document Summary
There are two approaches to study personality. To test ideas about personality we need to measure the personalities of many people, and then analyze and compare the measurements. If our measurements give meaningful differences between people, then we have an interval score: with interval scores we can calculate the means, standard deviations, correlations. When we measure psychological characteristics we find that many of them have a continuous distribution (which means that it is not categorical) Examples: testosterone levels and aggression, oxytocin levels and warmth, birth order and responsibility, physical attractiveness and self esteem etc. To calculate r, use each person"s z scores on the two variables, calculate the products and take the average. If you know a person"s z score on variable x, the correlation between variable x and variable y allows you to estimate the person"s z score on variable y: ex: zy = (zx)(rxy)