0346 GMT July 23, 2018
A baby is more likely to grow to have a squeaky voice if the index finger on their right hands is longer than the ring finger, dailymail.co.uk reported.
Researchers said the connection is probably the result of a lack of the hormone testosterone in the womb.
Testosterone is known to be key to early body growth and plays an important role in how vocal pitch develops during puberty.
The research, conducted by the University of Sussex, measured the voices of babies and infants aged four months and five years.
Fifteen children had their fingers measured and voices recorded on separate occasions to see if the two were linked.
The closer the index finger is in length to the ring finger, or even if it is longer, the child will likely have a higher pitched voice.
Strangely, this relationship — which was true of both young girls and boys — was only true of the fingers on the right hand.
Researchers said they were unsure whether the older children's pitch would last beyond puberty.
They wrote in their paper, “Pitch is a highly salient feature of the human voice that affects listeners' perceptions of femininity and masculinity in babies' cries, children's speech and adult speech.
“Here, we found that the pitch of babies' cries at four months of age was a significant and substantial predictor of the pitch of their speech at five years of age.”
The researchers believe the unique relationship exists because finger length and vocal pitch are both affected by the amount of testosterone in the womb.
Previous research has shown that men with high testosterone levels have a longer ring finger, likely because the hormone is involved in growth.
During puberty, testosterone causes the voice to change pitch, though this same link has not been made in younger children.
The researchers of the new paper said voice depth and finger ratio could be used to determine attributes related to gender, masculinity and dominance throughout the lifespan in future.
The researchers are hoping to see if this relationship stands true past puberty and into adulthood in upcoming research.