According to the organization Therapeutic Pathways, approximately 75 million people worldwide are diagnosed with autism spectrum disorder (ASD,) which corresponds to almost 1% of the global population. While extensive research has been done regarding ASD and certain traits people with the disorder may possess, much is still unknown regarding the specific psychological mechanisms that lead to these traits. Hongbo Yu, an assistant professor in the Department of Psychological and Brain Sciences at the University of California, Santa Barbara, helped devise an experiment to try to tackle some of the looming questions regarding these mechanisms, including the relative personality dimensions of people with ASD and those without, as well as both groups’ association between personality dimensions and facial recognition ability. Professor Yu, along with colleagues from West Virginia University, Dartmouth College, and Washington University in St. Louis, collected personality and facial recognition data from a large group of online participants, consisting of 89 self-identified ASD and 307 neurotypical controls, and then compared the data from neurotypical participants to that of participants diagnosed with ASD. They found that while people diagnosed with ASD did not differ significantly in personality dimensions such as empathy and social agreeableness, they exhibited altered neural coding of the specific social traits of trustworthiness and warmth, and thus were weaker than the control participants in their association between their own prosocial personality traits and their ability to judge the traits of trustworthiness and warmth in others. The study concluded that autistic traits are closely related to social anxiety and avoidance, but independent of empathetic and moral preferences, and ultimately shed light on the underlying mechanisms that can lead to certain social difficulties common with people diagnosed with ASD. 

Ancient Grains

New evidence from Belize suggests that more than half of the ancient Mayans’ ancestry can be traced back to early hunter-gatherers who migrated from South America a few thousand years ago, and who may have brought along a crop that would become one of the main sources of sustenance for one of the ancient world’s most famous cultures — maize. Corn has always been known to have played an important part of Mayan culture, but until recently researchers had no idea just how critical a role it played in the birth of Mayan civilization. Since 2014, researchers have unearthed more than 80 preserved skeletons from shallow graves in the Bladen Nature Reserve in Belize. This discovery allowed researchers to analyze DNA samples from the skeletons and compare them to the DNA of both ancient and living inhabitants of certain regions throughout Central and South America. They found that the more recent skeletons, dating from about 5600 years ago, contained DNA closely resembling that of a group of Indigenous people who today live from northern Colombia to Costa Rica. These findings suggest that approximately 5000 years ago there was a massive migration of people from further south up into the northwestern part of Central America, an area which would eventually become the home of the Mayan people. As for the relationship between the influx of migrants and the origin of maize cultivation, archaeologist Douglas Kennett at the University of California, Santa Barbara, has an answer. From analyzing teeth of these ancient hunter gatherer skeletons, it has been found that maize likely accounted for less than 10 percent of their diet, while skeletons dating from the post-migration period reveal maize accounting for about 10-50 percent of their diet. This evidence indicates that the early hunter-gatherers likely introduced new and improved maize plants, as well as a novel system of cultivation, into Central America when they migrated, ultimately influencing the development of one of the largest cultures of the Mesoamerican world. 

Beating the Heat:

While there is substantial existing data on the effects of extreme heat on human productivity and health, as well as new data on the health implications of COVID-19, researchers are now curious as to the joint effects of both of these factors. Professor David Lopez-Carr of the University of California, Santa Barbara, along with other contributors, helped lead research studying the effects of extreme heat and COVID-19 specifically on farmworkers, as they are one of the most susceptible communities to COVID-19, the least likely to get immunized, as well as the most exposed to extreme heat. While the paper has only been provisionally accepted into “Frontiers in Public Health,” Lopez-Carr and his team present questions regarding further research on this topic as well as outline potential policies, which if implemented could lead to enhanced wellbeing for farmworkers, through increased unemployment benefits and better labor regulations.

A version of this article appeared on p. 14 of the Mar. 31, 2022 print edition of the Daily Nexus.