_Iris Color and Psychomotor Performance

People with blue eyes or fair pigmentation have different brains and different behavior from darker people. Why? Because race isn't skin deep. It extends all over the body and into the deepest areas of the brain. This explains why so many golfers are blonds and so many basketball players are blacks.

This is discussed in depth on pages 94 and 95 of BIOLOGICAL PERSPECTIVES ON HUMAN PIGMENTATION by Ashley H. Robins, Senior Lecturer and Senior Consultant in Clinical Pharmacology, University of Cape Town Medical School and Groote Schuur Hospital. Cambridge, Cambridge University Press, 1991. Part of the Cambridge Studies in Biological Anthropology.
He refers to a book which happens to be available free online!

iUniverse Online Books

Are Blue-Eyed Children More Shy?

"Worthy (1974) put forward an interesting hypothesis. He claimed that dark-eyed individuals performed better at 'reactive activities' whereas light-eyed people were superior at 'self-paced activities'. A reactive activity is one where a response must be made appropriately and timeously to a situation over which the individual has little control. Examples of sports activities that are largely reactive in nature are boxing and basketball. A self-paced activity, on the other hand, requires an individual to choose his or her own time in which to respond to a situation. Golf and bowls are examples of self-paced sports."

Worthy, M. (1974). EYE COLOR, SEX, AND RACE: KEYS TO HUMAN AND ANIMAL BEHAVIORS. Anderson, South Carolina: Droke House/Hallux.

Worthy, M. & Markle, A. (1970). Racial differences in reactive versus self-paced sports activities. JOURNAL OF PERSONALITY AND SOCIAL PSYCHOLOGY, 16, 439-43.

Landers, D. M., Obermeier, G. E. & Patterson, A. H. (1976). Iris pigmentation and reactive motor performance. JOURNAL OF MOTOR BEHAVIOR, 8, 171-9.

Tedford, W.H., Hill. W. R. & Hensley, L. (1978). Human eye colour and reaction time. PERCEPTUAL AND MOTOR SKILLS, 47, 503-6.

Hale, B. D., Landers, D. M., Snyder Bauer, R. & Goggin, N. L. (1980). Iris pigmentation and fractionated reaction and reflex time. BIOLOGICAL PSYCHOLOGY, 10, 57-67.

"Wolf & Markle (1970) studied the statistics for various sports and concluded that Negroids were better at reactive than at self-paced games. There were few Negroid golfers or bowlers but excellent Negroid boxers. Even within a sport Negroids were better on the reactive tasks--for example, in baseball they were significantly more likely to be non-pitchers (reactive) than pitchers (self-paced); in basketball, Caucasoids were inferior to Negroids in field goal accuracy (reactive) but superior in free-throw accuracy (self-paced). In professional bowls light-eyed bowlers had higher money winnings than their dark-eyed counterparts. In the animal kingdom, too, a similar relationship prevails. Animals and birds that hunt by the self-paced techniques of stalking and surprise (e.g. cats, herons) are light-eyed whereas those that capture prey in a reactive manner by taking birds or insects 'on the wing' (e.g. swifts, swallows) are dark-eyed.

"Attempts have been made to corroborate Worthy's hypothesis and with some success. Several groups have demonstrated that dark-eyed subjects had faster reaction times than light-eyed subjects (Landers, Obermeier & Patterson, 1976; Tedford, Hill & Hensley, 1978; Hale et al., 1980). The faster reaction times were in response not only to visual but also to auditory stimuli. None of the investigating teams was able to offer a satisfactory explanation for their findings."
Explanations can be found in quotations and links in some of the forums below. It is explained by the complex relationship between melanin and dopamine in the brain.
Fair people and animals tend to have more dopamine in their brains because less dopa is diverted to make melanin outside the brain. One of the main functions of dopamine is attention. It takes careful attention to calculate a throwing or other action in advance.