Let’s talk nerdy about yawning lions, solving puzzles, feeding children, and more.
Why do humans and other animals yawn? Many theories attempt to explain the function of oscitation. Some studies suggest that yawning is the body’s way of increasing oxygen levels in the blood. Others connect yawning to survival in the wild or controlling brain temperature. A recent study indicates that yawning helps predators synchronize their movements.
University of Pisa ethologist Elisabetta Palagi was studying spotted hyenas in South Africa when she noticed the frequent yawing of a nearby group of lions. Palagi had previously studied contagious yawning in primates, so she wondered if the behavior in lions was socially linked.
For four months in 2019, she and her team made video recordings of the animals. They found that when a lion saw another lion yawn, the first lion was 139 times as likely to yawn within the next three minutes. The researchers also discovered that after catching a yawn, a lion was 11 times as likely to mirror the original yawner's movements compared to lions who had not seen the yawn.
Palagi says that yawning can indicate a shift between psychological or emotional states. This could be a way for an individual to communicate internal change to others in the group. She notes that while yawning is a widespread behavior, it remains mysterious because its function varies from species to species.
Plus or minus
Researchers at the University of Virginia in Charlottesville have found that adding resources tends to be the default action when people set out to solve a problem.
In a recent study, 1,585 participants were asked to tackle eight problems and puzzles by either adding or removing things. Most subjects chose addition over subtraction to complete each task. The researchers assumed that addition was the default choice because few people thought to subtract.
In the next set of experiments, they hinted that subtraction was an option by assigning a cost of 10 cents for each added piece.
Surprisingly, the financial penalty only influenced 40 out of 98 participants to use subtraction as a solution. In a later exercise, the researchers explicitly stated that adding a piece would cost 10 cents, but removal was free. This time 60 out of 99 chose subtraction.
The study suggests that defaulting to additive changes might be one reason we have overburdened schedules, cluttered houses, and bloated bureaucracies.
Feeding the gut
A report published by the World Health Organization in April 2020 states that 47 million of the world’s children are wasted (a form of undernutrition), and 14.3 million are severely wasted. While aid workers have been treating this condition by providing food, there may be a different solution.
In a recent study, researchers tested a new supplement designed to promote healthy gut bacteria against a leading treatment for malnutrition. The supplement is a mixture of chickpea, banana, soy, and peanut flours and oils called microbiota-directed complementary food No. 2, or MDCF-2. Toddlers in an impoverished Dhaka community who received the supplement showed signs of improved growth and more weight gain, despite having 20% fewer calories than children who took the other treatment.
MDCF-2 boosted blood components linked to the proper development of bones and the nervous and immune system. It also increased the presence of 21 types of beneficial bacteria.
Tahmeed Ahmed, head of the International Centre for Diarrhoeal Disease Research in Dhaka, Bangladesh, says that before MDCF-2 becomes a standard treatment, the team must develop a simpler formulation that can be stored for months. They must also conduct larger trials in other countries.
A license to eat
Here’s some more data from the World Health Organization. In 2016, over 1.9 billion adults were overweight. Six hundred fifty million were obese. Exercise is presumed to be useful for those trying to lose weight, but how does it affect food consumption?
Scientists at the Technical University of Munich and the University of Nebraska devised a study to find out what influence sport has on eating habits. The goal was to investigate the influence of exercise on decisions about food intake and timing.
In the study, 41 healthy participants aged 19-29 were assigned 45 minutes of exercise or a rest period of equal duration. The exercise group answered questions about hunger and satiety, preferred amount of food to eat, and food choice before they performed the workout.
They answered the questions again after exercising, and then a third time after a 30-minute break. The non-training group answered the same questions but had a rest break instead of the exercise session. The exercisers chose more food immediately after as well as 30 minutes after the workout. They also showed a preference for immediate food consumption at both times.
The researchers say the results suggest that after exercise, people like to reward themselves with extra helpings.
Someone to lean on
Is your romantic partner making your stress levels rise?
Paula Pietromonaco, professor emerita of psychological and brain sciences, studied more than 200 newlywed couples to see how their relationships affect health. She and her colleagues looked at how people responded to romantic partners’ depression or external stress.
The study found that relationship quality is better when a partner tries to listen without reacting, is supportive and helpful, and understands the other person’s needs. The researchers accurately predicted that a person with signs of mild to moderate depression would experience a drop in relationship quality during the study period. The drop was not seen in subjects with low depression scores and partners who were low in responsiveness.
The results for subjects with high depression scores who had responsive partners were the same as those of the low-depression group. Similar results were found in relation to external stress and partner behavior.
Pietromonaco says that people with vulnerability such as depression and external stress enjoy better relationship quality when their partner is supportive.