When Dr. William Allan paid personal visits to Watauga County residents in the early 1940s, he wanted to hear family stories. He wanted to know who had died and who was still living. He wanted to know what diseases ran through the generations and whether any strange features such as six-fingered hands may have recurred in the family tree. He wanted to know if any family members were "feebleminded."

Though it may have seemed odd that the head of the Department of Medical Genetics at the Bowman Gray School of Medicine would drop by hundreds of mountain homes, his visits were far from social. Allan was studying genetics in Watauga County - collecting the family trees of residents. His research would become the basis for much of the science that he and others did at Bowman Gray School of Medicine.

Allan spent much of his time in Watauga County visiting family reunions with an assistant. At every occasion, he would pull out a pad of paper and a pencil and - with the help of older family members - he would start drawing family trees.

The family trees are still at the Dorothy Carpenter Medical Archives at Wake Forest University School of Medicine. Five boxes overflow with hundreds of folders with family trees drawn by hand on draft paper.

Allan was attempting to trace the heredity of disease - serious conditions such as blindness and smaller defects such as extra fingers or toes that ran through families. He thought that his work would contribute to the small but growing body of knowledge about heredity.

He picked Watauga County for its small, multi-generational population. There had not been much in the way of immigration to the area, so the genetic lines had remained fairly pure, Allan explained in letters. He wanted to collect family trees - or pedigrees, as he called them - for all 18,000 people in the county. He nearly reached his goal, collecting about 75 percent on pedigrees that went back to the original settlers, before he died in April 1943.

The information he collected was never put together into one study. Instead, pieces of it were used in other studies. In 1954, Dr. C. Nash Herndon - Allan's protege - wrote a paper, "Intelligence in Family Groups in the Blue Ridge Mountains," that was based partly on Allan's study. The study used the IQ data that Allan had collected from 223 people in 86 families during the Watauga survey to study IQ differences between husbands and wives.

Herndon also used the pedigrees and Allan's other work to study the effects of marriages between cousins. The rate of first-cousin marriages in Watauga County was about 6.72 percent, well above the American and European averages of .2 to 1.03 percent. The increased rate did not affect the intelligence of the population, the study found.

Doing the studies took a special kind of person, Allan told Frederick Osborn, a nationally known eugenicist, in a letter dated Jan. 24, 1939.

"If you and Professor Dunn picked a man, with your gift of friendliness, it would be smooth sailing but a man with ... shyness and inhibitions, for instance, would be mistaken for one of General Sherman's stragglers and strung up. At this stage someone who has been trained to deal with the plain, common Scotch-Irish farmer would be more useful than someone trained in science."

Allan spoke from experience. While he generally got along well with the people he went to study, he had a few interesting moments, as Herndon and Allan's daughter recalled during an oral-history interview in 1976 arranged by the archives.

He was once mistaken for a Nazi spy. He had dogs set on him at least once. Another time, a dog helped him gain entry to a house. When the family dog didn't bite Allan while he waited at the gate for 10 minutes, the woman of the house agreed to talk to him.

But some Watauga County residents were suspicious of Allan's work for other reasons than simply being wary of strangers, especially when he attempted to take saliva samples with a small strip of paper.

"Well, I understand that word got around in the back country that they were sneaking around and sterilizing them with these things and the people didn't want to take it. At least some of them didn't," said Allan's daughter, Elizabeth Allan Berger, in the oral-history interviews.

"They thought that this was going to keep them from having children and ... so the men would, were, taking off but the ladies were crowding around," Herndon said.

• Danielle Deaver can be reached at 727-7279 or at ddeaver@wsjournal.com