Updated

Researchers say some human traits that are linked to sunlight, including a person's mood and sleep patterns, may be influenced by their Neanderthal forefathers.

A study of the genomes of over 100,000 Britons who inherited DNA from Neanderthal ancestors found they reported higher rates of listlessness, loneliness, staying up late and smoking.

Scientists at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, also confirmed that Neanderthals interbreeding with humans affected people's skin and hair color, though not in any single direction.

Michael Dannemann, who co-authored the study published Thursday in the American Journal of Human Genetics, said the findings suggest Neanderthals were already well-adapted to low and variable levels of sunlight in Europe when modern humans first arrived there from Africa some 50,000 years ago.