Eye colour and archery accuracy: Beer 1989 study

Eye colour made no difference to accuracy, but sex did: among the children, boys scored more points than girls. The study, two pages long, involved 126 people from a school district in eastern Kansas: 47 pupils in their seventh year of school, 49 in their eighth and 30 adults who had been shooting for one to six years. The idea came from earlier work suggesting that dark-eyed people respond better to external cues and light-eyed people rely more on internal ones; in a self-paced action such as shooting, the difference might have shown.

Among the children, over 20 arrows with a maximum of 100 points, boys averaged 40.57 and girls 23.84, a clear gap. Between light and dark eyes, and between the two school years, the differences were not significant, and there were no interactions between the factors. Among the adults, over 60 arrows with a maximum of 300, those with dark eyes averaged 238.44 points and those with light eyes 225.42, a difference the test did not find significant. Men and women were not compared in the adult group: there were only three women.

Testing took place on an indoor range, at a target of concentric rings, with a miss worth 0 and the centre worth 5. The seventh-year pupils shot 20 arrows from 20 feet (about 6 metres), the eighth-year pupils 20 arrows from 30 feet (about 9 metres), and the adults 60 arrows from 20 yards (about 18 metres). The children used school bows and arrows, the adults their own equipment, of a type that is not stated. Eye colour was self-reported and split only into light and dark.

For the children the authors ran an analysis of variance with three factors (eye colour, sex and school year), and for the adults one with eye colour alone. The table gives means and standard deviations for every subgroup: among the children, for instance, dark-eyed boys scored 40.96 and light-eyed boys 40.25, and among the girls 24.90 and 23.42.

The sample is one of convenience and badly unbalanced: the adults were 27 men and 3 women, none of them dark-eyed, and there were only 4 dark-eyed girls in the eighth year. Previous experience was not controlled, and for the children the paper only says that most had little. The two school years shot at different distances, so the comparison between them mixes age with distance, and the lack of a difference means little.

The gap between boys and girls may come from many things the study does not measure, such as strength, experience, or the school bows, which the paper does not describe and which may have been harder for some to draw. There are also typographical slips: for the adults the test is given as F = 0.48 with p < 0.05, which from the text should read p > 0.05, and in the table dark-eyed men have a standard deviation of 53.90 while their group, which is the same people, has 33.90. No effect sizes are reported.

For archers, and for those who teach them, the study settles a curiosity: in this group eye colour had nothing to do with accuracy, either in children, most of them with little experience, or in adults with a few years' practice. It is a small result, from few arrows at short distances, and there is no reason to expect anything different further out, but the study does not show it.

The gap between boys and girls should not be read as a limit on girls as archers. With bows supplied by the school and no control for previous experience, it may reflect strength, familiarity with the action or equipment more than the ability to aim. The study measures neither strength nor draw weight, so it cannot say which of these explanations matters.