13.14 Influence of age and sex on motor performance. The slowing of motor performance as humans age is well established. Differences across the sexes, however, are less so. A recent study assessed the motor performance of 246 healthy adults.10 One task was to tap the thumb and forefinger of the right hand together 20 times as quickly as possible. The following table summarizes the results (in seconds) for seven age classes and two sexes:
| Males | Females | ||||||
|---|---|---|---|---|---|---|---|
| Age class (years) | n | s | n | s | |||
| 4 | 19 | 4.72 | 1.31 | 19 | 5.88 | 0.82 | |
| 5 | 12 | 4.10 | 1.62 | 12 | 5.93 | 1.13 | |
| 5 | 12 | 4.80 | 1.04 | 12 | 5.85 | 0.87 | |
| 6 | 24 | 5.08 | 0.98 | 24 | 5.81 | 0.94 | |
| 6 | 17 | 5.47 | 0.85 | 17 | 6.50 | 1.23 | |
| 7 | 23 | 5.84 | 1.44 | 23 | 6.12 | 1.04 | |
| > 75 | 16 | 5.86 | 1.00 | 16 | 6.19 | 0.91 | |
Generate a plot to look at changes in the time across age class for each sex. Describe what you see in terms of the main effects for age and sex as well as their interaction.