Finger length indicates risk of schizophrenia

The results of the investigations often surprise us and can seem very debatable at times. As strange as the conclusions of a study published in the journal Clinical Anatomy, the length of the index and ring finger, as well as the asymmetry of both hands, could predict the schizophrenia in males.

What is schizophrenia?

Schizophrenia is a psychotic disorder that causes a serious distortion in thought and perception of reality. People who suffer from this serious pathology experience hallucinations (visual or auditory), delusions, loss of contact with reality or a disorder of self-perception, among others symptoms. Schizophrenics also often suffer from loss of motivation, lack of energy, emotional disturbances, or social withdrawal.

In Spain, this disorder affects half a million individuals, and its onset usually occurs during the adolescence (although also in childhood) or early adulthood. It seems that in men it starts at an earlier age than in women.

Although it is not known for sure what causes schizophrenia, there seems to be some consensus that it has to do with a combination of genetic and environmental factors.

As shown by a study of the Center for Biomedical Research in Mental Health Network (CYBERSAM), patients with schizophrenia have a life expectancy of between 10 and 20 years less than people without this affectation.

The study and the conclusions

The study, published by Clinical Anatomy, was carried out by researchers in Turkey who measured the length of 103 men with schizophrenia, then compared the data with the length of the fingers of 100 healthy men.

For the study finger ratio was calculated (the length of the index finger divided by the length of the ring finger) and the researchers found that men with schizophrenia had a longer index finger and a shorter ring finger. This only occurred in the right hand, since no significant differences were found in the left hand. This asymmetry between the hands of people with schizophrenia is known as the “skewness index”.

According to the director of the research, Dr. Taner Oznur, "the asymmetry index has potential utility as a diagnostic test to determine the presence of schizophrenia."

According to the researchers of the investigation, the key may lie in the testosterone.

Much past research has shown that exposure to abnormal testosterone levels in utero (during the fetus) can have a negative impact on brain development, increasing the risk of schizophrenia and other disorders mental. Furthermore, the same testosterone exposure in utero can also affect the size and length of the fingers.

But does this indicate that finger length predicts schizophrenia? Not exactly, because although there is a correlation between the length of the fingers and schizophrenia, this does not mean that it is due to a causal relationship, it may be due to other variables or just random. What does seem clear is that this research will lead to future research in this line to rule out or confirm these results.

On the other hand, this study has only been carried out with men, the results with women could be different.

Other results in the same line of research

This is not the first time that researchers have associated "finger ratio" with behavior. Previous studies have affirmed that there is a relationship between the ratio of the fingers and the sexual orientation, the infidelity, academic performance, physical aggression, either heart disease.

Bibliographic references

• Abdullah Bolu, Taner Oznur, Sedat Develi, Murat Gulsun, Emre Aydemir, Mustafa Alper, Mehmet Toygar. The ratios of 2nd to 4th digit may be a predictor of schizophrenia in male patients. Clinical Anatomy, 2015; DOI: 10.1002/ca.22527