Cohort
a group of people sharing a common characteristic, such as from a given time period
crystallized intelligence
our accumulated knowledge and verbal skills; tends to increase with age
fluid intelligence
our ability to reason speedily and abstractly; tends to decrease with age, especially during late adulthood
cross-sectional study
research that compares people of different ages at the same point in time
longitudinal study
research that follows and retests the same people over time
How stable are intelligence test scores over the life span?
The stability of intelligence test scores increases with age. By age 4, score fluctuate somewhat but begin to predict adolescent and adult scores. By early adolescence, scores are very stable and predictive.
intellectual disability
a condition of limited mental ability, indicated by an intelligence test score of 70 or below and difficulty adapting to the demands of life (Formerly referred to as mental retardation)
down syndrome
a condition of mild to severe intellectual disability and associated physical disordered caused by an extra copy of chromosome 21
giftedness
high-scoring people tend to be healthy and well-adjusted, as well as unusually successful academically