Study reveals orangutan behavior influenced by laughter

A study published on October 21, 2026, in the journal Biology Letters suggests that orangutans may be influenced by the laughter of their peers when making decisions about where to search for food.

Researchers tested orangutans at two European zoos

Daan Laméris and Erica Cartmill from the University of Indiana conducted experiments involving six orangutans, four males and two females aged 8 to 51 years, observed at Planckendael Zoo in Belgium and Indianapolis Zoo. The animals had an average age of thirty years.

Orangutans were trained to find hidden food

The study involved a five-day protocol in which the orangutans were taught to dig up peanuts or almonds hidden under different materials, such as wood chips. During the experiment, researchers used recorded laughter to influence the orangutans' choices.

Laughter affected food-seeking decisions

The results indicated that four of the six orangutans preferred to search for food in locations associated with laughter, even though the reward was identical on both sides. This suggests that the laughter of orangutans may act as a signal that enhances the perceived value of a reward, influencing their decisions based on the emotional context of the moment.

Researchers link laughter to positive mood

The researchers propose that this preference indicates a more positive mood during the learning phase, implying that the animals not only remember where food is hidden but also retain the positive association with that specific moment.