Play is critical for kids’ development — but ‘play’ in research is often defined by adult scientists, not the children themselves. To understand what kids really need, a team of scientists in Denmark asked them, developing a special questionnaire based on children’s own words to rate play experiences. They found that children’s idea of ‘good’ play sometimes isn’t what adults would consider ‘nice’ play, potentially involving competition or mischief — but in order to have fun, kids always need social alignment with their peers and opportunities to take part. The researchers say these results show kids need more agency in how they play. 

A newly discovered fossil ape from northern Egypt is reshaping the understanding of early hominoid evolution, say researchers. The fossil finding suggests that the closest ancestors to modern apes may have emerged in northern Africa, outside the traditionally studied regions of East Africa. “[The] findings […] confirm that paleontologists might have been looking for crown-hominoid ancestors in the wrong place,” write David Alba and Júlia Arias-Martorell in a related Perspective. Dating to about 17-18 million years ago, the new species – Masripithecus – represents the closest known hominoid relation to the lineage that ultimately gave rise to all living apes, including humans. Today, it is widely accepted that the earliest apes (stem hominoids) originated in Afro-Arabia during the Oligocene Epoch, more than 25 million years ago, and diversified there before spreading into Eurasia by roughly 14 to 16 million years ago, during the Miocene. However, the emergence of modern apes – the group that includes all living species and their last common ancestor – remains uncertain, as fossils from this period are scarce, widely dispersed, and difficult to interpret. This uncertainty is compounded by the uneven fossil record in Africa, where discoveries have been concentrated in only a few regions, leaving much of the potential ancient range of Miocene-age apes unexplored.

Here, Shorouq Al-Ashqar and colleagues describe a newly identified fossil ape discovered in the Wadi Moghra region in northern Egypt, which lived ~17-18 million years ago. According to the authors, this new species, named Masripithecus moghraensis, adds to our understanding of early ape diversity and evolution at a pivotal moment when Afro-Arabia was becoming connected to Eurasia, enabling the spread of species out of Africa. To determine where this species fits into the evolutionary tree of humans, Al-Ashqar et al. employed a modern Bayesian “tip-dating” approach, which incorporates both anatomical traits and fossil ages to estimate relationships and divergence times. Their analysis suggests that Masripithecus represents the stem hominoid that is most closely related to the lineage that ultimately gave rise to all living apes. The authors argue that the findings support the notion that modern apes may have originated in northern Afro-Arabia, the Levant, or the eastern Mediterranean.

In an unprecedented observation, researchers captured the birth of a sperm whale calf, documenting how 11 whales from two normally separate family groups coordinated closely to support the newborn for hours after its arrival. These findings offer quantitative evidence of direct communal caregiving in cetaceans and suggest that short-term, highly coordinated cooperation during critical moments like birth may play a foundational role in maintaining the complex social structures seen in sperm whale societies. The evolution of cooperation remains a fundamental question in biology, particularly among highly social, long-lived mammals such as toothed whales. Species like sperm whales exhibit remarkably intricate social systems, in which stable, matrilineal family units cooperate in activities such as foraging and communal caregiving. Birth represents a critical and high-risk moment for the animals, as whale calves require immediate support to survive, making it a uniquely revealing context for understanding cooperative behavior. However, studying these deep-diving creatures in the open ocean represents a significant challenge and direct observations of sperm whale births are exceedingly rare. As a result, the cooperative behavior in sperm whale births has long remained a mystery. 

Here, Alaa Maalouf and colleagues present a detailed, high-resolution analysis of a sperm whale birth by integrating drone video footage, machine learning, and long-term data on social relationships and kinship. In July 2023, off the coast of Dominica, Maalouf et al. observed 11 members of a known sperm whale social unit, comprising two typically separate and unrelated family groups, gathering unusually close to the surface. Although these subgroups are generally distinct in their foraging behavior and social associations, they formed a cohesive cluster as a birth unfolded. Using drone footage, the authors documented the 34-minute delivery of a calf, followed by a period of intense, coordinated activity in which multiple adult females surrounded the mother. According to the authors, in the hour after birth, the group displayed strikingly cooperative behavior; individuals from both family groups took turns physically supporting and lifting the newborn to the surface, likely assisting it in breathing. The entire unit remained tightly organized during this critical period. In addition, there were close passes by Fraser’s dolphins and brief interactions with pilot whales. Several hours after the birth, the sperm whale cluster gradually dispersed into smaller, more typical foraging groups.

Artificial intelligence (AI) chatbots that offer advice and support for interpersonal issues may be quietly reinforcing harmful beliefs through overtly sycophantic responses, a new study reports. Across a range of contexts, the chatbots affirmed human users at substantially higher rates than humans did, the study finds, with harmful consequences including users becoming more convinced of their own rightness and less willing to repair relationships. According to the authors, the findings illustrate that AI sycophancy is not only widespread across AI models but also socially consequential – even brief interactions can skew an individual’s judgement and “erode the very social friction through which accountability, perspective-taking, and moral growth ordinarily unfold.” The results “highlight the need for accountability frameworks that recognize sycophancy as a distinct and currently unregulated category of harm," the authors say.

Research on the social impacts of AI has increasingly drawn attention to sycophancy in AI large language models (LLMs) – the tendency to over-affirm, flatter, or agree with users. While this behavior can seem harmless on the surface, emerging evidence suggests that it may pose serious risks, particularly for vulnerable individuals, where excessive validation has been associated with harmful outcomes, including self-destructive behavior. At the same time, AI systems are becoming deeply embedded in social and emotional contexts, often serving as sources of advice and personal support. For example, a significant number of people now turn to AI for meaningful conversations, including guidance on relationships. In these settings, sycophantic responses can be particularly problematic as undue affirmation may embolden questionable decisions, reinforce unhealthy beliefs, and legitimize distorted interpretations of reality. Yet despite these concerns, social sycophancy in AI models remains poorly understood.

To address this gap, Myra Cheng and colleagues developed a systematic framework to evaluate social sycophancy, examining both its prevalence in popular AI models and its real-world effects on those who use them. Using Reddit community “AITA” posts, Cheng et al. evaluated a diverse set of 11 state-of-the-art and widely used AI-based LLMs from leading companies (e.g., OpenAI, Anthropic, Google) and found that these systems affirmed users’ actions 49% more often than humans, even in scenarios involving deception, harm, or illegality. Then, in two subsequent experiments, the authors explored the behavioral consequences of such outcomes. According to the findings, participants who engaged with sycophantic AI in regard to interpersonal scenarios, particularly conflicts, became more convinced of their own correctness and less inclined to reconcile or take responsibility, even after only one interaction.  Moreover, these same participants judged the sycophantic responses as more helpful and trustworthy, and expressed greater willingness to rely on such systems again, suggesting that the very feature that causes harm also drives engagement. “Addressing these challenges will not be simple, and solutions are unlikely to arise organically from current market incentives,” writes Anat Perry in a related Perspective. “Although AI systems could, in principle, be optimized to promote broader social goals or longer-term personal development, such priorities do not naturally align with engagement-driven metrics.”

Podcast: A segment of Science's weekly podcast with Myra Cheng, related to this research, will be available on the Science.org podcast landing page [http://www.science.org/podcasts] after the embargo lifts. Reporters are free to make use of the segments for broadcast purposes and/or quote from them – with appropriate attribution (i.e., cite "Science podcast"). Please note that the file itself should not be posted to any other Web site.

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