WEDNESDAY, Jan. 26 (HealthDay News) -- Children are not born with a dread of snakes or spiders but learn these fears very quickly, a new study suggests.

In one experiment from the study, the researchers showed two videos side by side to children as young as 7 months. One video showed a snake and the other showed something non-threatening, such as an elephant. At the same time, the infants heard a recording of either a happy or fearful voice.

The infants spent more time looking at the snake video when they heard a fearful voice, the researchers reported, but the children showed no sign of fear themselves.

In another experiment, 3-year-olds were shown a screen of nine photographs and asked to select a target item. The children identified snakes more quickly than flowers and more quickly than other animals that look similar to snakes, such as frogs and caterpillars.

Children who were afraid of snakes identified snakes just as quickly as did children who did not have that fear.

"What we're suggesting is that we have these biases to detect things like snakes and spiders really quickly, and to associate them with things that are yucky or bad, like a fearful voice," researcher Vanessa LoBue, of Rutgers University, said in a news release from the Association for Psychological Science. The study is published in the association's journal, Current Directions in Psychological Science.

Earlier research, LoBue said, showed that adults quickly recognize the difference between scary and not-so-scary creatures. The new study confirmed that children do the same, but that it's a learned, not innate, response, she said.

More information

Helpguide.org explains how to overcome fears and phobias.