MORRISTOWN, N.J. (CBSNewYork) – A new study on guide dogs for the blind suggests that pups are more successful when they are given tough love.

At just over seven weeks old, golden retrievers, chocolate, black and yellow labs are already being trained at The Seeing Eye in Morristown, New Jersey.

They will learn to interact with others, adapt to new surroundings and remain calm while under stress – skills that researchers have lined to how the puppies were raised.

The new study finds “more intense mothering… was associated with program failure,” and “mothers whose nursing style required greater effort… were more likely to produce successful offspring.”

“One of the findings was that pups who were perhaps overly mothered – their moms were overly attentive to them, spending a lot of time with them, licking them copiously – that those pups were not as likely to be selected as guides,” Director of Canine Medicine & Surgery Dr. Dolores Holle says.

The ability to overcome obstacles, whether it be to find food or navigate a street curb, is a key factor in the success of a seeing-eye dog.

Instructor Joan Markey says dogs who exhibit a fear of the unknown don’t make the cut.

“If they’re afraid of the world, they are not going to be a good guide,” she says. If they get worried by loud traffic, people making loud noises, anything that makes them afraid to the point where they want to bolt and run, that would get them out of the program.”

About 70 percent of dogs who enter guide dog training programs are successful.