A CIESE Collaborative Project

CIESE: Human Genetics: Survey Traits

Observable Genetic Traits

Earlobes: Free ear lobes (dominant trait) vs. Attached ear lobes (recessive trait)
Free earlobes are those that hang below the point of attachment to the head. Attached ear lobes are attached directly to the side of the head.


Forelock: White forelock (dominant trait) vs. No white forelock (recessive trait)
A white forelock is a patch of white hair, usually located at the hairline just above the forehead. See photo below.

Dimples: Dimples (dominant trait) vs. No dimples (recessive trait)
Dimples are natural dents in the face to the right or left of the mouth. If a person has only one dimple, they should be counted as having dimples.

Thumbs: Straight thumb (dominant trait) vs. Curved thumb (recessive trait) When viewed from the side as in the illustration below, curved thumbs can be seen as part of a circle.


Straight pinky (recessive trait) vs. Bent pinky (dominant trait) Hold your hands together as if you are covering your face. If the tips of the pinkies (or baby fingers) point away from one another, the pinkies are bent .

Mid-digit hair: Mid-digit hair (dominant trait) vs. No mid-digit hair (recessive trait) Look for hair only on the finger shown by the white arrow below.