Czech researchers claim to have found that “previously published results on the 2D:4D ratio are biased by its covariation with finger length”. What are the implications?
Popular magazines in The Netherlands & Germany have picked-up the scoop with tempting titles such as: ‘Finger ratio is misleading’ and ‘Deceptive finger’. But the truth appears to be that those titles could be more misleading: for, likely the new research describes a new milestone in the digit ratio research!
|The Czech researchers presented their new research under the title: ‘differences in the 2nd to 4th digit length ratio in humans reflect shifts along the common allometric line‘ – and in the publication they describe the following about their finger findings:
“Sexual differences in 2D : 4D are mainly caused by the shift along the common allometric line with non-zero intercept, which means 2D : 4D necessarily decreases with increasing finger length, and the fact that men have longer fingers than women.”
“We do not claim that the previous results for the finger length ratio are wrong”
“We conclude that previously published results on the 2D : 4D ratio are biased by its covariation with finger length. We strongly recommend regression-based approaches for comparisons of hand shape among different groups.”