What have a number of recent studies indicated happened with intelligence levels since the late 1990s?
A) Mean IQ scores have accelerated upward
B) IQ scores are maintaining a consistent trajectory
C) IQ scores have flattened
D) IQ scores have flattened and started to decline

Question

Quizplus · Accepted Answer

Recent studies have indicated that IQ scores, after a period of increase, have flattened and even started to decline since the late 1990s. This phenomenon has been observed in several countries and has sparked discussions about the causes behind this trend.

What Have a Number of Recent Studies Indicated Happened with Intelligence