Answer:  Have you ever wondered if you had an identical twin somewhere who not only looked like you but made uncannily similar life decisions, liked and disliked the same things, and had the same habits? Identical twinship is so fascinating because of what it tends to indicate about nature vs. nurture, including how intelligence and talents are genetic or environmental.

On average, identical twins raised together tend to be around 80 percent the same in everything from stature to health to IQ to political views. The similarities are partly the product of nurture, or similar upbringing. But evidence from the comparison of twins raised apart points rather convincingly to genes, or nature, as the source of a lot of that likeness. In the most widely publicized study of this type, launched in 1979, University of Minnesota psychologist Thomas Bouchard examined 60 pairs of identical twins raised separately, but who displayed personalities, behaviors and social attitudes that were remarkably alike. Check out some of the freakish similarities of these identical twins that were reared apart:

As children, Jim L. and Jim S.  each had a dog named Toy. Each bit his fingernails and, since age 18, had suffered from mixed headache syndrome. Each had been married twice, first to a Linda and then to a Betty. One twin had named his son James Alan, and the other, James Allen. Each had put a circular bench around a tree in his garden. Each had worked at a gas station and later part-time in law enforcement as a sheriff. Each chain-smoked Salems and preferred an occasional Miller Lite beer. Each scattered love notes to his wife around the house. Every summer, each had driven his family in a light blue Chevrolet from Ohio to the Pas-Grille Beach in St. Petersburg, Florida, for their summer vacation. They had similar voices, hand gestures, and mannerisms.

Gerry and Mark were nearly bald and had bushy mustaches. Each was a volunteer firefighter and made his living installing safety equipment. Each wore aviator glasses, big belt buckles, and big key rings. Each drank Budweiser with his pinky hooked on the bottom of the can and crushed the can when he finished. Both had the same distinctive laugh, both were partial to Italian and Chinese food, and both enjoyed hunting and fishing.

Jack and Oskar were identical twins born in Trinidad in 1933 and separated in infancy by their parents’ divorce. Oskar was raised by his Catholic mother and grandmother in Nazi-occupied Czechoslovakia and he joined Hitler Youth. Jack was raised by his Jewish father in Trinidad and became an officer in the Israeli navy. Each wore aviator glasses and a blue sport shirt with shoulder plackets, had a trim mustache, liked sweet liqueurs, stored rubber bands on their wrists, read books and magazines from back to front, dipped buttered toast in coffee, flushed the toilet before and after using it, enjoyed sneezing loudly in crowded elevators to frighten other passengers, and routinely fell asleep at night while watching television. Each was impatient, squeamish about germs, and gregarious.

Bessie and Jessie each had a bout of tuberculosis, and they had similar voices, energy levels, administrative talents, and decision-making styles. Each had her hair cut short in early adolescence. Jessie had a college-level education, while Bessie had only 4 years of formal education; yet Bessie scored 156 on an IQ test, while Jessie scored 153. Each read avidly, which may have compensated for Bessie’s poor education. She seemed to have created an environment compatible with her inherited potential.

Daphne and Barbara both had miscarriages the same year, followed by the births of two boys and a girl. They admit that they’ve also cooked the same meal from the same recipe book on the same day. They have been called the “giggle twins” because they laugh and fold their arms the same way.

Of course, there are differences in these twins too. And most of the other twins in the study weren’t nearly as alike as these examples. Furthermore, since no one is claiming there is a gene for flushing the toilet before you use it, or a gene for marrying women named Betty, such coincidences are statistical anomalies. These quirky cases strengthen our sense of the power of nature, but they don’t provide enough data to make a scientific case. On average, identical twins raised separately are about 50 percent similar — and that defeats the widespread belief that identical twins are carbon copies. Obviously, they are not. Each is a unique individual in his or her own right. So if I have an identical twin out there, feel free to e-mail me and we’ll compare IQ’s (betcha I’d win!).