Studies continued to find that e-cigarettes are harmful in numerous ways, and the degree of harm varies among Banana Pudding (Southern Style), Hot Cinnamon Candies, and Menthol Tobacco flavors. Airplane noise at 85 decibels induces a taste preference for umami, and cabin pressure induces a preference for tomato juice. The oldest broken bone of a land animal was identified as the right radius of a tetrapod who fell from a height of at least 85 centimeters 333 million years ago. The earliest evidence of human-on-human violence, from 430,000 years ago, was discovered in Spain. Baboon abuse was common among the upper classes of pre-pharaonic Hierakonpolis. One third of all floods in the southwestern Netherlands in the past half-millennium were acts of war. In Hawaii, a man and a swordfish stabbed and killed each other. “The whole harbor was scared of him,” said the man’s sister-in-law. Endangerment may be driving the smalltooth sawfish to parthenogenesis. The moonfish was found to be warm-blooded. Parakeets are the only non-mammals to yawn contagiously. Rogue waves are not totally unpredictable.

The larynx muscles of mice, the opioid receptors of human brains, and memories that have been lost through amnesia can all be activated with light. Boys who smoke marijuana go through puberty earlier than nonsmoking boys but are 4.6 inches shorter by age twenty. Pedophiles selected for study by taking a volume-based phallometric test for erotic preference were likelier to be left-handed and to have congenital facial malformities, and less likely to have malformed extremities. Fecal samplings by Linda Vigilant found negligible levels of inbreeding between mountain gorilla fathers and daughters, in part because the daughters avoid mating with males who are old enough to be their fathers. Evolutionary biologists who enforced monogamy among flour beetles over fifty generations theorized why males and sex are necessary. The first fraction of human ejaculate contains the best sperm, while the remainder exists mostly to foil competition. Altruistic children tend to be healthier but from poorer families. Autistic Norwegians confess to their crimes. German psychoinformaticians analyzed the emotional range of Forrest Gump. Britons who are both psychotic and autistic are more empathetic than those with only one of the two conditions. Bipolar Brazilians tend to possess three or more of the following attributes: at least two apparent tattoos, at least three foreign languages, at least three religion changes, at least three marriages, at least sixty lifetime sexual partners, regular infidelity, circadian dysregulation, heavy cursing, high debt, and pathological love; if they are male, they are more likely than unipolar Brazilians to have a talent for poetry, and if they are female, they are more likely to read frequently and dress extravagantly.

Men who smell a T-shirt recently worn by a fertile woman drink more nonalcoholic beer. Periodic text messages improve teenage girls’ compliance with injection-based birth control. Male New Zealand pea crabs, who live alone in green-lipped mussels, spend hours tickling the lips of a female’s mussel to gain admittance and mate with her. Burmese long-tailed macaques in Thailand favor one-handed strikes with sharp stones to crack open sessile rock oysters. Brown thornbills attacked by pied currawongs mimic the cries of Accipiter hawks. The powerful are desensitized to injustices affecting others but hypersensitive to injustices affecting themselves. Intermittent declines in the use of prosocial language by members of Congress between 1996 and 2014 were linked to decreases in approval ratings. Prosocial behavior was observed in subjects who were awed, variously, by footage of droplets of colored water falling into a bowl of milk, slowed down 200 times; by footage of “threatening natural phenomena” such as tornadoes and volcanoes; and by standing in a grove of 200-foot-tall Tasmanian eucalyptus trees.

“Wilderness’s Soul I,” a photogram mounted on linen, by Zhang Dali. Courtesy Pékin Fine Arts, Beijing and Hong Kong