By many accounts, 2024 was a year of brain health, with researchers reporting ways to improve infant neurodevelopment and identifying new factors to protect the brain as it ages.
For the publishers of the Oxford English Dictionary, however, 2024 was the year of brain rot.
"Brain rot" is a term that describes either the cause or effect of spending hours online viewing trivial information. It communicates concerns about the impact of consuming excessive amounts of low-quality online content, especially on social media, Oxford University Press language experts said.
After first gaining traction on TikTok, its use surged by 230% between 2023 and 2024, they pointed out. Following a public vote involving more than 37,000 people, "brain rot" was deemed the 2024 .
"I find it fascinating that the term brain rot has been adopted by Gen Z and Gen Alpha, those communities largely responsible for the use and creation of the digital content the term refers to," President of Oxford Languages Casper Grathwohl said in a statement.
"These communities have amplified the expression through social media channels, the very place said to cause brain rot," Grathwohl continued. "It demonstrates a somewhat cheeky self-awareness in the younger generations about the harmful impact of social media that they've inherited."
Psychologist Andrew Przybylski, PhD, of the Oxford Internet Institute at the University of Oxford in England, agreed.
"There has been a lot of skepticism around technology in the past decade, a period that some have called the 'techlash,'" Przybylski told 鶹ý.
"As more of our day-to-day lives happen online, it makes sense that we attribute whatever happens -- good or bad -- to the technologies that enable these interactions. There are endless media headlines demonizing technology, plus our own experiences of frustration on top of this," he continued.
"The term 'brain rot' captures this pessimism and dissatisfaction," Przybylski said. "It offers us a real opportunity to stop and ask ourselves: Why are we using technology? What are we getting out of it? How can we live with it differently?"
In 2023, the U.S. Surgeon General issued an about social media and youth mental health, acknowledging that while some habits might lead to potentially harmful brain changes, social media can have benefits, too.
Not all screen time is harmful, Przybylski observed. "The scientific consensus -- whether it be from the or the on self-harm -- is clear that the links between health and screen time are more nuanced and less definitive than some would have us believe," he noted.
The term "brain rot" was first recorded by Henry David Thoreau, who used it in 1854 to critique society's tendency to devalue complex ideas and favor simple ones.
"While England endeavors to cure the potato rot, will not any endeavor to cure the brain-rot -- which prevails so much more widely and fatally?" Thoreau wrote in Walden.
The desk where Thoreau first wrote the words "brain rot" sits in the Concord Museum in Massachusetts. "When Thoreau refers to 'brain rot,' he is talking about the ill effects of only consuming texts that have one straightforward meaning, rather than engaging with texts that are layered with multiple opportunities for interpretation," said museum curator David Wood.
"In this way, he used the term just as we would today to express concern about our tendency to consume 'trivial' content," Wood told 鶹ý.
Over time, the concept of brain rot evolved. Modern-day usage may be an outgrowth of the decades when the term described excessive time spent watching TV, a habit linked with worse brain outcomes in people of all ages.
In children and adolescents, duration of TV viewing has been associated with in cross-sectional and longitudinal analyses. A 20-year study that followed young adults from age 30 on showed that greater amounts of TV viewing were associated with . And a U.K. Biobank study reported that among people 60 and older, higher levels of cognitively passive sedentary activities like watching TV raised the risk of .
David Raichlen, PhD, of the University of Southern California Los Angeles, who led the U.K. Biobank study, told 鶹ý that this risk "was at least in part independent from an individual's physical activity levels." In models adjusted for a wide range of covariates including physical activity, sedentary time spent passively watching TV was associated with a 24% increased risk of incident dementia over 12 years.
"While time spent sitting in general seems linked with poor brain health, spending time watching TV or engaged in other passive behaviors may be the most detrimental way to be sedentary," Raichlen said.