Women have long been told to look to mom or grandma for signs of the hair loss patterns they will likely one day inherit, but new studies reveal that a crop of external factors can have an even more damaging effect on the thickness and fullness of women’s hair.In a study of 84 identical female twins, marital status emerged as the leading forecaster for thinning hair. Widows and divorcées experienced greater amounts of hair loss than their married counterparts—a phenomenon that scientists attribute to the effects of stress on the body. Researchers used sets of identical twins, as they would genetically carry the same possibility of hair loss. This makes other influences that might cause the siblings to deviate from a predetermined hair pattern clearer to discern.QUIZ: How Stressed Are You?“While genetics remain a strong predictor of some types of hair loss, introducing certain stressful or unhealthy factors into a person’s life can result in more hair loss,” says study co-author Bahman Guyuron, M.D., who will present his findings at the American Society of Plastic Surgeons (ASPS) annual conference this month.QUIZ: Are You Eating the Right Foods for Your Hair?Other factors that contributed significantly to hair loss included heavy smoking (tied to temple hair loss) and large weekly intake of alcohol (linked to thinning along the front hairline). Meanwhile, women who drank up to two alcoholic beverages a week showed significantly less hair loss than their twin, which one could conjecture to be the result of the calming effect of moderate amounts of alcohol consumption.While the medical community may be marveling at the results of the study—which has documented many of the hair loss factors for the first time—hair stylists have long anecdotally known that emotionally-taxing experiences of heartbreak and loss can trigger hair loss in women.RESEARCH: Hair Loss May Signal Health Problems“As soon as a client asks me if their hair is thinning, my next question is to ask what’s going on with them,” says Natasha Sunshine of L.A.’s Byu Ti Salon. “Nine times out of ten, there is something pretty big happening.”Sunshine’s first recommendation is to combat the stress with breathing techniques and practices like yoga to target the cause of the hair loss, and to take supplements rich in biotin, folic acid and amino acids to help give hair the nutrients it needs to grow back healthy and full.MORE: Restaurant Meals for Fuller HairAnd the older a woman gets, the more susceptible she is to hair loss tied to emotional trauma, says New York salon owner Angelo David—who specializes in extensions, and sees a continuous stream of thinning hair clients daily. “I have definitely seen how tragic moments can affect not only women’s hair, but also their overall sense of wellbeing,” says David.But before you hang on to a bad relationship for the sake of your hair, know that evidence also exists that says leaving a rocky relationship can be vital to your health.In one study, researchers outfitted 42 couples with tiny suction devices that caused small blisters on their arms. Fighting couples experienced a 40 percent slower healing rate than the amicable partners, which meant two extra days needed to heal.The body’s slower ability to regenerate under duress could also help explain why other studies have shown that women in hostile relationships who get a divorce live longer on average than those who choose to stay.QUIZ: How Healthy is Your Hair?