You never know when inspiration for a new research project will strike. It was a conference keynote about climate and children that grabbed Jorge Cuartas’ attention. “It made me think that this was going to be the next big topic in social sciences—understanding how climate change is going to affect human behavior, health, and societal well-being more broadly,” says Dr. Cuartas, a developmental psychologist with a background in economics.
Climate was a new realm for Dr. Cuartas, an assistant professor in the Department of Applied Psychology at NYU Steinhardt and Director of the Catalyzing Action for Resilient Ecologies (CARE) Lab. His focus has mostly been the developmental consequences of violence on young children—and working on violence prevention programs. But intrigued, he eagerly jumped in and quickly discovered ample research on the effects of climate change on livelihoods, physical health, and mental health. He also found a glaring gap: Most studies concerned adults and adolescents. “I could not find anything about young children, so I began working on developing theoretical frameworks, systematic reviews, and now empirical research specifically for young children’s development,” he says.
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Early cognitive, social, emotional, and motor skills and early brain development are, Dr. Cuartas says, highly predictive of learning, physical health, mental health, and economic trajectories throughout life. “So I became interested in understanding the potential consequences of climate hazards on those foundational developmental skills,” he says. An article about his—and his fellow researchers’—findings, “Ambient Heat and Early Childhood Development: A Cross-national Analysis,” was published in the Journal of Child Psychology and Psychiatry in December 2025.
Answering key questions
There were several questions Dr. Cuartas was hoping to answer, key among them was whether exposure to excess heat could affect early developmental skills, specifically cognitive, social, emotional, and motor skills. “We were also interested in understanding that if there were any effects, whether those effects were equally distributed for different children, or whether there were differences in these consequences according to children’s characteristics and the characteristics of their households, families, and communities,” he explains.
They relied on public data collected by UNICEF from a survey called the Multiple Indicators Cluster, which is active in multiple countries, plus other polling data called ERA5-Land, a monthly climate data set with information on temperature and precipitation. The six countries they focused on were Georgia, Namibia, Madagascar, Malawi, Sierra Leone, and the state of Palestine.
“We found that children who were exposed to temperatures higher than usual for a given region and a given season were less likely to be developmentally on track. This is basically showing us that excessive heat can increase the risk for developmental problems and also compromise the global policy goals that we have in general,” he explains. Specifically, they found that exposures to temperatures above 30 degrees Celsius (86 Fahrenheit) or higher could reduce the probability of being developmentally on track by between five and eight percentage points. “A sizable effect,” he says. These effects were the same for boys and girls and were stronger for children living in poorer households and urban areas, where heat tends to concentrate, as well as for kids in households lacking clean water and sanitation.
How heat slows childhood development
There are multiple ways heat can slow development. The most immediate is that our systems interpret heat as potentially harmful. “Our bodies are attuned to a particular temperature. Excessive heat can be interpreted as a threat, and with young children, that translates into segregation of cortisol and other stress hormones. If it happens chronically, this can affect brain and skill development,” he says.
While adult bodies tend to manage extreme heat by redistributing blood toward the skin and sweating, young children’s underdeveloped bodies don’t do this well. “Their bodies are not as efficient as adults in releasing heat. Heat tends to concentrate more, and that can lead to multiple consequences in brain and biological development,” says Dr. Cuartas. Excessive heat can also undermine sleep quality, which is critical early in life for developing biological systems.
Dr. Cuartas points out two additional relevant psychosocial pathways. The first is that excessive heat can hinder learning opportunities both in and outside the home. “On hotter days, children tend to spend more time in sedentary behaviors and less time in physical activity. That reduces their learning and opportunities to interact with peers and other adults,” he says. His final observation is where his violence work meets his newer climate work: “Heat can increase aggression. With my colleagues, we also published a paper showing that excessive heat can also increase violence against children within the family system,” he notes, adding that in a week following a heat wave, the probability of physical punishment and psychological aggression increased. This too can impact childhood development.
Takeaways and next steps
“My hypothesis is that these effects are quite universal and will vary according to characteristics. For example, in households with access to air conditioning, maybe they are way more protected,” he says.
Dr. Cuartas hopes people who come across his research will be inspired to consider very young kids and not just adults when thinking about addressing climate change. “There’s growing recognition and interest in working on disaster preparedness and preparedness for excessive heat, but it’s very rare that these policies and plans include young children. It’s important that we start to acknowledge their specific needs.” Social scientists can have a role in helping parents help children deal with the many impacts of a rapidly warming climate. “We can consider way more explicitly how climate hazards may affect some of the outcomes we are interested in in relation to development and education,” he notes.
Meanwhile, Dr. Cuartas is continuing his climate research. Now he wants to understand how the timing of exposure matters when it comes to childhood development—whether excessive heat during pregnancy or in the first year or whenever matters the most. From there, he’s interested to figure out how best to include these topics in parenting programs and other ways to reach and educate impacted families.
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