Gary Smalley and Rex Russell compiled the following research that was most revealing in their book Food and Love,:
Medical research has studied the effect of chronic quarrelling on a person's health and have found that couples and roommates who frequently quarrel tend to have more illnesses than do the people in amicable relationships. Those who have constant fights suffer a weakening of their immune systems and are generally less healthy than those who react amicably with friends and family. A study of students at Yale University discovered that roommates who disliked each other had far more colds and flues and visits to physicians than did roommates who liked each other and the greater the dislike-the higher the number of illnesses.
Researchers of Ohio State University Medical Center brought 90 couples into lab and asked them to resolve an issue of disagreement; continuous blood monitoring for 24 hours revealed that couples who had high levels of hostility displayed significant deterioration on eight measures of the immune system. Researchers at Cambridge University in England found that couples who had constant quarrels were 13 times as likely to develop a serious illness as couples who rarely fought.
