Social media algorithms are designed to predict what users are likely to engage with, but researchers warn they can also encourage excessive use and steer people towards harmful content.
The systems used by platforms including TikTok, Facebook, Instagram and YouTube select posts and recommendations based on users’ online activity and personal information such as age, location and interests.
Technology companies closely guard the programming behind these systems, which can determine what appears in users’ feeds, Japan Today writes.
Researchers and activists say features such as endless scrolling, intermittent rewards and time-sensitive notifications can encourage people to remain online longer than intended.
"These platforms have engineered addictive features that keep children and adults online longer than they intend, often at the expense of sleep, wellbeing and real-world connection," Mark Williams, honorary professor of cognitive neuroscience at Macquarie University, said.
In a landmark trial in Los Angeles this year, technology companies were accused of creating "addiction machines".
University of Leicester lecturer Quynh Hoang said unpredictable rewards could activate the brain's dopamine system.
"This unpredictability triggers the dopamine system, creating a compulsive cycle of seeking and anticipation," Hoang wrote.
Researchers have also warned that recommendation systems can lead users towards increasingly provocative or extreme material.
The recommendations "are designed to hold our attention, and too often that means privileging provocative and extreme content because outrage drives engagement and engagement drives profit", Steven Roberts at Monash University said.
One concern is the spread of so-called "manosphere" content among teenage boys. These online communities and influencers promote misogyny and, in some cases, violence against women.
Research by men's health charity Movember found that social media could guide young men from seemingly innocuous content about subjects such as sport and exercise towards more extreme material.
"We can already see the consequences in Australian schools," where "misogyny is rife", Roberts said.
"Our national survey of more than 2,600 teachers found that... 70 per cent had frequently or occasionally seen the impact of manosphere social media influencers present on student attitudes and behavior."
Australia's proposed rules
Australia is considering legislation that would allow social media users to opt out of algorithm-driven feeds, while also requiring major platforms to take greater responsibility for protecting under-18s from harmful content.
The proposed rules would cover pornography, online bullying and material that glorifies crime or encourages eating disorders.
The "my feed, my way" initiative would instead allow users to see updates from friends, family and pages they follow.
"The government has handed Australians a switch. Whether anyone flips it is another matter," Lisa Harrison, a lecturer in communication and media at Flinders University, said.
A 2025 survey of more than 6,000 people across six countries found that only one in five respondents would switch off personalised recommendations if given the option, Harrison said.
"The algorithm is good at its job, and the minority who do opt out will find a feed of friends and creators feels quieter than the one they left."
By Aghakazim Guliyev
