The impact right or left handling has on development may determine emotional consequences

Dec 14, 2010
An experimenter handling a foal by “rubbing” it vigorously. Credit: Séverine Henry

Certain events experienced at the moment of birth have consequences on the emotional reactions of animals at an adult age. French researchers from the Laboratoire d'Ethologie Animale et Humaine have tested the effects of unilateral tactile stimulation on newborn foals. Their results show that animals handled on their right side at birth avoid contact with humans more often than those stimulated on their left side or not at all. Published in Biology Letters, this work raises questions on the organization of neonatal care in animals and humans.

Events experienced by influence their behavior in the more or less long term. Certain events in early life are crucial for the behavioral and of animals and can have a considerable impact on the organization and the development of brain asymmetry in particular.

Having observed that handling at birth can have long term effects, a team from the Laboratoire d'Ethologie Animale et Humaine wondered what impact unilateral stimulation would have on later in life. The ethologists tested the consequences of unilateral tactile stimulations on 28 newborn foals: 10 of them were handled just after birth on their right side (the newborn foals were “rubbed” vigorously for one hour on a single side), 9 others on their left side, while the remaining 9 were not handled at all. The researchers then observed medium-term effects: the reactions of foals to a human approach, when they were 10 days old, differed according to the side stimulated at birth. The right-handled fled at the approach of humans more often than the left-handled or unhandled foals.

These results show that tactile stimulation at birth has a medium-term impact, the extent of which depends, among other things, on the side of the stimulation. Consequently, these experiments on foals demonstrate that handling a newborn on the right side or the left side does not have the same consequences. Scientists will henceforth study this unilateral sensitivity in newborn babies in maternity wards, with a view to improving in humans and thus the well-being of infants.

Explore further: Oregon food label measure headed for recount

More information: Differential outcomes of unilateral interferences at birth. Alice de Boyer des Roches, et al. Biology Letters, 2010

add to favorites email to friend print save as pdf

Related Stories

How a baby's nose knows Mom's scent

Jul 06, 2005

For newborn mammals, including humans, identifying Mom by her odor can be critical to maternal bonding and survival. However, researchers have not understood how this odor identification develops. Now, Kevin Franks and Jeffry ...

Recommended for you

Oregon food label measure headed for recount

Nov 25, 2014

Tallies of the last remaining ballots show an Oregon measure that would require labeling of genetically modified foods lost by only 809 votes and is headed for an automatic recount.

How photosynthesis changed the planet

Nov 20, 2014

Two and a half billion years ago, single-celled organisms called cyanobacteria harnessed sunlight to split water molecules, producing energy to power their cells and releasing oxygen into an atmosphere that ...

From dried cod to tissue sample preservation

Nov 19, 2014

Could human tissue samples be dried for storage, instead of being frozen? Researchers are looking at the salt cod industry for a potential tissue sample drying technology that could save money without sacrificing tissue quality.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.