What is Hitchhiker's thumb? What does it tell about your personality?

Hitchhiker's thumb term is used to refer to a hypermobile or extremely flexible thumb. Person who owns such a thumb can hyper-extend it. It means the person can bend the thumb backward beyond the normal range of motion. It can be bilateral.

Hitchhiker's thumb

In this entity, the person can extend the thumb to even upto 90 degrees. Thumb has only 2 phalanges instead of 3. And the hyperextension occurs at the interphalangeal joint. In this state of hyperextension, it looks like the thumb out that a person who wants to hitch a hike does. 

Prevalence of hitchhiker's thumb

This thumb is often seen in many people but the exact prevalence has rarely been found out. In the USA, there is an old survey of 1953 of John Hopkins University that revealed that 24.7 percent of white people and 35.6 percent of Black people had it. This is the first study of this condition. In 2012, there was a study done in South Nigeria. It showed that 32.3 percent of randomly selected 310 people (male and female) had hitchhiker’s thumb. Of these, 15.5 percent were male, and 16.8 percent were female. 

Hitchhiker's thumb (Source: Healthline)

 Reason for hitchhiker's thumb

It is a genetically transmitted condition and the mode of inheritance is recessive. If both parents have the gene for it, the child has 25% chance of getting the condition. If one parent has the gene and not the other parent, then the child will not have it. Those who have the recessive gene for this condition but do not express it due to the presence of dominant gene of thumb straightness are called carriers. But the expression of people with hitchhiker's thumb varies from minimal to full-blown. 

The condition is otherwise painless and not associated with any abnormal function. This condition may be associated with other  medical conditions such as Diastrophic dysplasia or Hypermobility spectrum disorder. In these patients, problems and pain might occur due to the primary disease. 

Significance of hitchhiker's thumb

Per se, the hitchhiker's thumb is not an issue. Hence not significant. But there are some myths about personality associated with it. People are grouped into following 5 categories based on their thumb structure and extensibility:

1. Same length phalanges of thumb: The person with such a thumb is balanced and desires harmony and peace. The individual is calm and good in talking and teaching. The person is a good adviser with lot of empathy. 

Types of thumbs (Source: Brightside)

2. Distal phalanx is longer: Such a person is a perfectionist. He or she is never satisfied with details and always feel that there is something more to achieve. Idea obsession is noticed but the person finds a modest way out for success. The person is honest and respected for it. 

3. When the first phalanx of the thumb is longer: the person is a hard worker. Life is not so easy but the person does not surrender and finds a way to overcome obstacles and emerge victorious. Such people are smart and confident. They hold clear ideas with no confusion and are considered reliable. 

4. When thumb is not flexible, the person is stubborn and dominating. But they keep promises and can come to know when a person is taking undue advantage of them. 

5. When thumb is flexible and hitchhiker type, the person is a flexible person. The person does not hold egos and can adapt to situations well. 

Also read What is Morton's toe?