Changing patterns of intellectual strengths and weaknesses in males with fragile X syndrome.

The team looked at how thinking skills change with age in boys with fragile X.

They gave IQ and achievement tests to males of different ages.

Then they compared scores to see which abilities keep growing and which stop.

Sequential skills, like repeating a string of numbers, plateau around age ten.

Simultaneous skills, like solving a puzzle, keep rising into adulthood.

Reading and math scores also keep climbing after ten.

Cryan et al. (1996) saw the same age-ten wall, but in daily-living skills.

Their fragile X boys gained adaptive skills until ten, then flattened.

Together the papers show ten is a key turning point for both brain and life skills.

Belmonte et al. (2008) later called fragile X a moving continuum, not a fixed label.

They folded the plateau finding into this bigger picture.

Mayes et al. (2003) tracked IQ profiles in autism and found different curves.

Their kids kept gaining verbal IQ past preschool, unlike the fragile X plateau.

The contrast warns us not to treat all ID diagnoses the same.

When you test a fragile X boy over ten, skip heavy sequential tasks.

Pick simultaneous tests like pattern boards or reading probes instead.

Use this cutoff to split groups in studies or to set age-matched controls.

Share the curve with teachers so they expect skill plateaus and keep goals realistic.