The idea that a behavior will increase or decrease based on the consequences that follow that behavior is crucial to ________

External Validity is ONLY concerned with whether the results from a study can be generalized back to the population of interest.

a. true b. false

When Schaie tested adult intelligence using a cross-sequential research design, he found

a gain until the late 50s in all but one ability. moderately large decrements in all areas from age 40 to age 50. stability until the mid-30s and decline thereafter. that beyond age 60, only some abilities decrease.