This type of research suggests that there is a correlation between general intelligence (g) and physiological factors such as development stability and general physical fitness. One might develop the research question further by investigating whether intelligence can be manipulated by means of increasing actual physical fitness levels by means of exercise, for example. Since it has long been an accepted fact that the body and mind function as a mutually influencing unit within the human organism, it follows that manipulating the human body would also manipulate the mind, and by association the g-factor.

A comparison can also be made between existing, natural fitness, without any manipulation efforts by the individual, and the degree of g manifest in the individual. By making such a comparison, a conclusion can be drawn regarding the degree of correlation between g and natural body symmetry. This can then be used as a springboard for further investigation into the manipulation of the body, as mentioned above, and the influence of this on cognitive outcomes.

A large amount of literature is available on the g-factor and the correlation...

The research strategy will therefore focus on searching for and finding items that include the g-factor and how this is related to specific intelligence tests. Developmental factors will also be taken into account during the research. The practical section of the research will focus upon testing three groups: a group of people whose physical body symmetry is high without apparent manipulation by individuals; a group who has worked to achieve a high level of physical fitness; a group whose natural body symmetry and physical fitness are low. Comparisons will be made among the results.
References

Colom, R., Jung, R.E. And Haier, R.J. (2006). Distributed brain sites for the g-factor of intelligence. NeuroImage No. 31. Retrieved from: http://www.mrn.org/pubs/Colom%20Distributed%20Brain%20Sites.pdf

Prokosch, M.D., Yeo, R.A. And Miller, G.F. (2005). Intelligence tests with higher g-loadings show higher correlations with body symmetry: Evidence for a general fitness factor mediated by developmental stability. Intelligence, No. 33. Retrieved from: http://www.unm.edu/~psych/faculty/articles/yeo/9.pdf