Rebecca says "Milk spill" to which her grandfather replies "Yes, the milk spilled on the floor." This is an example of

Suppose that you are listening to a lecture by a speaker who supports the critical period hypothesis for a particular motor skill in children. The speaker is likely to say that

a. the ability to acquire this skill increases gradually over time. b. the ability to acquire this skill shows an abrupt increase during development. c. children will show a gradual decline in acquiring the skill competently, as the age of acquisition increases. d. children will show an abrupt drop in acquiring the skill competently, as the age of acquisition increases.

A method of studying developmental changes by comparing people of different ages at about the same time is a ______ study

a. cross-sectional c. longitudinal b. strain d. biographical