Table 1
Mean (± standard error) results for digit ratio and digit length (cm) for all 90 participants.
| Males | Females | P | d | |
| R2D:4D | 0.959 ± 0.004 | 0.977 ± 0.005 | 0.01 | -0.59 |
| L2D:4D | 0.957 ± 0.004 | 0.968 ± 0.005 | 0.10 | -0.36 |
| DR-L | 0.002 ± 0.003 | 0.008 ± 0.004 | 0.17 | -0.29 |
| R2D | 7.44 ± 0.07 | 6.86 ± 0.06 | <0.0001 | 1.34 |
| L2D | 7.41 ± 0.07 | 6.82 ± 0.05 | <0.0001 | 1.48 |
| R4D | 7.76 ± 0.07 | 7.02 ± 0.06 | <0.0001 | 1.71 |
| L4D | 7.75 ± 0.07 | 7.05 ± 0.06 | <0.0001 | 1.63 |
P-values are reported from an analysis of variance by sex. Cohen's d measures the effect size for sex differences.
Figure 1
Acrophase for Right and Left Hands of Male vs. Female Subjects. Mean (± standard error) acrophase for right and left hands of males and females across 3 days. Females peaked earlier in the day than males in the right (*p = 0.002) and left (**p = 0.008) hands. The right hand peaked before the left in combined subjects (paired t-test; p < 0.01).
Figure 2
Correlation Between Male and Female ME Survey Scores and Right Hand Acrophase. Correlation between Morning-evening activity preference (ME Survey) and acrophase. ME survey scores correlated with right hand acrophase (shown) in males (A, Pearson's r = -0.55, p = 0.0001) and females (B, Pearson's r = -0.34, p = 0.02); ME survey scores also correlated with left hand acrophase (not shown) in males (Pearson's r = -0.56, p < 0.0001) and showed a correlation trend in females (Pearson's r = -0.25, p = 0.09). The negative correlation indicates that the higher the ME score, the earlier the acrophase is reached (indicating more morning-type tendencies). Mean right acrophase is denoted by a dashed line.
Table 2
Pearson's correlation coefficient between digit ratio and measures of circadian wrist activity.
| Males | Females | |||
| R2D:4D | L2D:4D | R2D:4D | L2D:4D | |
| Mean Acrophase | 0.08 | -0.05 | -0.06 | -0.04 |
| R Acrophase | 0.06 | -0.06 | -0.10 | -0.04 |
| L Acrophase | 0.12 | -0.04 | -0.02 | -0.04 |
| AcrophaseR-L | -0.24 | -0.12 | -0.24 | -0.004 |
| Mean Activity | -0.16 | 0.04 | 0.02 | 0.06 |
| R Activity | -0.04 | 0.13 | 0.03 | 0.08 |
| L Activity | -0.21 | -0.03 | -0.01 | 0.03 |
| ActivityR-L | 0.22 | 0.16 | 0.06 | 0.10 |
| ME Survey | -0.03 | 0.01 | 0.02 | -0.24 |
All correlations were non-significant.
Figure 3
Right and Left Mean Acrophase for Young vs. Older Male and Female Subjects. Right (A) and Left (B) mean acrophase (± standard error) for young and older males and females. Males are shown in black (young) and dark gray (older). Females are shown in white (young) and light gray (older). There were main effects for sex (p = 0.002) and age (p = 0.040). The four age and sex groups analyzed show peak activity at different times of the day. The order is as follows ("<" means "peaks before"): older females < young females < older males < young males.
Figure 4
ME Survey Scores for Young vs. Older Male and Female Subjects. Morning Evening Preference (ME) scores from the Horne-Ostberg questionnaire for young and older males and females. Males are shown in black (young) and dark gray (older). Females are shown in white (young) and light gray (older). There were main effects for sex (p = 0.02) and age (p = 0.02). The four age and sex groups analyzed show ME scores in the following progression: older females > young females > older males > young males. The higher the ME score, the greater the preference for morning activity.
Table 3
Pearson's correlation coefficient between mean digit length and measures of circadian wrist activity.
| Males | Females | |||||
| 2D | 4D | D | 2D | 4D | D | |
| Mean Acrophase | 0.15 | 0.13 | 0.14 | 0.08 | 0.11 | 0.10 |
| R Acrophase | 0.14 | 0.13 | 0.13 | 0.12 | 0.16 | 0.14 |
| L Acrophase | 0.16 | 0.13 | 0.15 | 0.04 | 0.06 | 0.05 |
| AcrophaseR-L | -0.11 | -0.02 | -0.07 | 0.23 | 0.28 | 0.27 |
| Mean Activity | 0.10 | 0.12 | 0.11 | 0.03 | 0.01 | 0.02 |
| R Activity | 0.11 | 0.08 | 0.10 | 0.09 | 0.06 | 0.08 |
| L Activity | 0.07 | 0.13 | 0.10 | -0.04 | -0.04 | -0.05 |
| ActivityR-L | 0.02 | -0.08 | -0.03 | -0.22 | 0.16 | 0.19 |
| ME Survey | 0.02 | 0.04 | 0.03 | 0.03 | 0.09 | 0.06 |
| HHP | -0.19 | -0.10 | -0.15 | 0.09 | 0.01 | 0.05 |
All correlations were non-significant.