Given the claim in the title they talk about "men and women". So the sample size is small because:
1) zero variance in location
2) very little variance in age (all undergraduate) (variances of the ages: 1.33 to 7.19, so 70% of their samples all were in two age ranges, one 3 year wide, one 14 year wide)
3) cultural variation : essentially zero (?) they didn't even bother to check AFAICT
1) zero variance in location
2) very little variance in age (all undergraduate) (variances of the ages: 1.33 to 7.19, so 70% of their samples all were in two age ranges, one 3 year wide, one 14 year wide)
3) cultural variation : essentially zero (?) they didn't even bother to check AFAICT