heartline

A heartline, also known as the simian crease or single palmar crease, is a single crease that runs across the palm of the hand instead of the usual two or three. It is formed when the upper and lower creases of the hand, known as the head line and life line, merge into one. This crease can occur on either the dominant or non-dominant hand, or on both.

The occurrence of a heartline is a natural genetic variation and is not associated with any specific medical condition. While it has been a subject of interest in palmistry, where it is sometimes interpreted as indicating a concentrated emotional nature or a strong will, these interpretations are not scientifically supported.

Studies suggest that the heartline occurs in approximately 1 in 30 people, with a slightly higher prevalence in males. It can be present from birth and may or may not be inherited. The formation of the crease is determined early in fetal development. While its presence has no bearing on an individual's health or personality in a medical or psychological sense, it is a distinctive feature that some people find interesting.