Psychology over Physiology or Physiology over Psychology. This question has always intrigued me. Man is a sum of his Physiology and Psychology, however the question is whether both are important in equal proportion or does one dominate over the other.
Modern history of mankind is full of instances where some obvious physical shortcomings were overcome by strong psychological resolve. Yet during moments of physical illness we must have observed its impact on our mental health.  Again, many doctors indicate that recovery from illness varies from person to person due to difference in respective psychological make-up. The one with strongest psychological resolve demonstrates capability of not only recovering fast but sometimes even recovering from a hopeless terminal illness. Louise Hayhouse is one such example. This sort of tilts the balance in favor of Psychology.
Hellen Keller was born with some very severe physical disabilities because of which she suffered from severe psychological issues. Yet it was her psychological resolve that helped her overcome her disabilities and become an icon that she eventually became. There was also the case of Dr Roger Bannister who for the first time in the history of mankind ran a mile under 4 mins. One could possibly argue that his particular physical disposition made it possible to do so; however the fact that after him people have continued to break that barrier till it stopped being a barrier anymore indicates something that happened beyond the physical realm. 
At this stage Psychology seems to be asserting its dominance over physiology. Let me see if we could even things out. Physical damage to brain has been known to have severe impact on a person’s psychology. Genetics also has been found to have its say and no amount of psychological resolve has been effectively proven to have any impact on it. As the physical health fails through life the psychological resolve also demonstrates a similar decline. Yet there have been many instances where perfectly healthy and physically fit individual go through phases of deep depression and psychological disorder. One could argue that a person who does rigorous physical activity or exercise aids release of a certain hormone that helps in keeping depression or stress at bay. Yet suicide among Indian farmers is so common. Nobody could possibly be working physically as harder as a farmer yet some seemingly insurmountable barrier pushes him to suicide. Also the moment a physical exercise or activity to improve psychological well-being is proposed it sort of points out which is the means and which is the ends. Then again physical exercise is prescribed just for physical well-being as well.
Roman poet Juvenalwrote the famous words mens sana in corpore sano which translated to English means Healthy Mind in a Healthy Body. However he didn’t indicate which the pre-condition is. Even Vivekananda, a person known to have delved the depths of psychological world advised people to maintain a healthy body as ‘that’ he says ‘is the essential instrument provided to man through which one could exert control over mental faculties’. Much like the chicken and egg question this debate about dominance of psychology or physiology suffers from a circular argument. The only conclusion that I am able to draw is that Psychology is dominant and has the power to overcome obvious Physiological shortcomings only if the physiology is at a certain optimal level. Best of physical conditioning fails to prevent psychological imbalances or disorder. The balance seems to be firmly shifting in favor of Psychology.