Crossed Up: Does Crossed Hand/Eye Dominance Affect Basketball Shooting Percentage? Science Fair Project By: Amir Almusawi

Purpose/Problem The purpose of this experiment is to learn about crossed hand eye dominance and help increase free throw percentage in basketball. This project is designed to look for consequences of having the dominant hand and eye on the same side of the body (uncrossed) vs. having the dominant hand and eye on opposite sides of the body (crossed).

Research Data from previously done experiments support our hypothesis. One experiment done by Keith Hines and Robert Thurman stated that crossed hand-eye dominant people have a higher free throw percentage than uncrossed hand-eye dominant people. Another experiment proved the same results. This project was conducted by Ashton W. Pomrehn, who found that crossed hand-eye dominance has a positive effect on basketball players. It makes logical sense that crossed hand-eye dominance would have a positive effect on free throw percentage because if you have uncrossed hand-eye dominance, your dominant eye is blocked by the hand shooting the basketball.

Research count..d Some key terms are: dominance- the normal tendency for one side of the brain to be more important than the other in controlling certain functions, as speech and language: crossed- mixed, usually with two components; and, eye dominance- the tendency to prefer visual input from one eye to the other. More key terms are: hand dominance- the preference of one hand to perform fine and gross motor tasks; and, crossed hand eye dominance- having opposite dominances in eyes and hands. There are a few key points to know while conducting this experiment. "Eye Dominance" refers to the eye that the brain "prefers" or one that has stronger "processing" in the brain than the other. People usually have one eye that likes to "take over" when binocular vision is impaired, or one eye that is more sensitive to visual discrimination.  During suppression, when the brain "chooses" to process only one eye, the other eye is in essence "shut down". Usually it makes no difference in correcting for visual defects with eyeglasses or contacts.

Research count..d If one is crossed hand-eye dominant, then their shooting percentage will increase because when players shoot free throws, they often hold the ball up at face-level when preparing for the shot. In this position, the ball can easily the eye on the same side of the body as the shooting hand. For shooters with uncrossed hand and eye dominances, this would mean that the dominant eye was partially blocked. For shooters with crossed hand and eye dominances, this would mean that the non-dominant eye was partially blocked. The independent variable is if you are cross hand-eye dominant, and the dependent variable is how many free-throws you make. Eye dominance refers to the eye that the brain prefers, or one that has stronger processing in the brain than the other. People usually have one eye that likes to take over when binocular vision is impaired, or one eye that is more sensitive to visual discrimination. During suppression, when the brain chooses to process only one eye, the other eye is in essence shut down. Usually it makes no difference in correcting for visual defects with eyeglasses or contacts.

HYPOTHESIES If 20 people shoot free throws in this experiment, then people with crossed hand-eye dominance will make more free throws then those without crossed hand-eye dominance.

Independent Variable The independent variable to this experiment is if you are crossed hand-eye dominate.

Dependent Variable The dependent variable is how many free throws you make.

Control The control to this project is being crossed hand/eye dominate.

Material List Pen/pencil Paper 10 people Clipboard Basketball court

Procedure First, gather 20 people Then gather information about the participants such as name, age, etc. Have each person test to see whether they are crossed hand-eye dominant or not the person would extend both hands away from the body and place the hands together making a small triangle (approximately 1/2 to 3/4 inch per side) between the thumbs and the first knuckle. With both eyes open the person would then look through the triangle and center something such as a doorknob in the triangle. Close the left eye .If the object remains in view, the subject would be right eye dominant. If the subject’s hands appear to move off the object and move to the left, then the subject would be left eye dominant. After, record if the person is right or left handed. If the person has different hand and eye dominance, then mark them down as crossed hand-eye dominant. Next have the person shoot 5 free throw shots at a basketball hoop with their dominant hand. Finally record whether or not the shot was made.

Data Table Subject Age Dominant Hand Dominant Eye Crossed or Uncrossed? Shots Made Subject 1 12 Right Uncrossed 8 Subject 2 13 Left Crossed 9 Subject 3 Subject 4 Subject 5 Subject 6 Subject 7 7 Subject 8 10 Subject 9 6 Subject 10

Observation Log While people were shooing I noticed that everyone that was crossed eye was having the same movement. That’s really when I understood the science of simply shooting a basketball.

Graphs

Results The results were very scattered, and the hypothesis of my experiment was proved wrong. It is now understood that hand eye dominance does not effect free-throw shooting as much as the hypothesis stated. Some further investigations could include testing if crossed hand-eye dominance effected hand-eye coordination, if air pressure will affect the dynamics of ball bouncing, or if bodies are left-dominant or right-dominant effects any certain thing.

Conclusion After gathering our data, it was concluded that crossed hand-eye dominance doesn’t have much of an effect on free throw shooting percentage. The hypothesis stated that crossed hand-eye dominance will help basketball players score free throws because, when players shoot free throws, they usually hold the ball up at face level, which can easily block the eye on the side of the shooting hand. On the other hand, shooters with crossed hand-eye dominance would have their non-dominant eye partially blocked, which wouldn’t affect them much. The results, on the other hand, didn’t agree with our hypothesis. When subjects shot a free throw both crossed and uncrossed averages resulted in a 8-shot-made average. From the averages we collected, the hypothesis was inaccurate.

Bibliography Hines, K., & Thurman, R. (2007, April 2). Ballin': The Effect of Hand and Eye Dominance on a Subject's Free. Kirillov, A., & Beverly, C. (2011, October 9). Determining your Dominant Eye. McWilliams, K., & Armstrong, P. (1998, November 28). What is Eye Dominance? Olson, A., Ph.D. (2007, October 1). Crossed Up: Does Crossed Hand/Eye Dominance Affect Basketball Shooting Percentage? Retrieved October 15, 2011