During an eight-month-long research trip to the Democratic Republic of Congo (DRC) and Zambia, we studied consolation: the way bonobos and chimpanzees comfort each other after conflicts and distress. But early on, we kept noticing something that didn’t quite fit.

The animals were exchanging a lot of friendly physical contact, embracing, touching and kissing, in competitive situations before any clear conflict or distress signals had broken out. We started wondering what all that touching was actually for.

Our new research into how great apes manage social stress suggests it could be quite important, and that this behaviour dates back at least 6 million years, long before our species evolved. Like us, our closest ape cousins, the bonobos and chimpanzees, also navigate stressful and competitive situations every day.

One example is when they discover a tree laden with ripe fruit. Everyone wants to eat and conflicts of interest can often lead to fights. But something else caught our attention. More often, apes reach out to one another with friendly touch: embracing, patting and making gentle contact.

Our colleague Edwin van Leeuwen, a Dutch biologist, had developed a feeding task to measure social tolerance across great ape groups. This task is called the peanut swing. It involves filling a bamboo trough with peanuts and swinging it over the fence so the food lands in front of the apes. This spreads peanuts evenly across a small area while researchers record who gets food, and how much. We used this test to measure whether groups could share resources peacefully in close proximity.

Because the apes watched the trough being filled, we could observe how they behaved as anticipation built. Friendly touch clustered in the minutes just before the food arrived. Previous researchers called this celebration behaviour. But discovering food is not just a cause to celebrate. It is also tense and risky.

Could friendly physical contact be helping to keep that tension at bay?

To find out, we measured a five-minute anticipation period before the food was released. We watched everything the apes did: friendly contact like kissing, embracing and patting, as well as aggression and threats. Over several months, we filmed 116 apes from five groups across 60 sessions at two African sanctuaries, Lola ya Bonobo in the DRC and Chimfunshi in Zambia.

In both species, the answer was clear. Bonobos and chimpanzees who engaged in more reassuring friendly contact before the food arrived spent significantly more time feeding peacefully alongside others afterwards. This pattern held across most groups and was strongest in the most tolerant ones. Researchers consider tolerance – the willingness to share space without aggression – to be the foundation of cooperation and social learning across the animal kingdom. Our findings suggest that pre-emptive friendly touch may be part of how that tolerance is maintained.

The patterns followed the social structure of each species. In bonobos, female-female pairs were the most likely to show friendly reassurance. This reflects how bonobo society works: females form strong alliances to counter male aggression and occupy high status positions. In chimpanzees, it was males who reassured each other most, reflecting the importance of male coalitions in their societies.

For both apes, these patterns were clearest in the more tolerant groups. In groups with more authoritarian leaders, the pattern disappeared.

Some of the most striking behaviour we saw were among the chimpanzees. During tense moments, they placed fingers, hands and other body parts inside each other’s mouths. They also held each other’s genitals. For a species known for lethal aggression, these are extraordinarily risky things to do.

Perhaps the vulnerability is itself the signal of trust. You only offer a risky contact if you are confident the other animal won’t bite. And this communicates something important about how you see the relationship.

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Read more: Inside the sex lives of chimpanzees: it’s about much more than just reproduction

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Touch is among humanity’s oldest forms of communication. Skin-to-skin contact between infants and caregivers is one of the first channels through which attachment forms, long before language develops. A 2006 study found holding a romantic partner’s hand can reduce threat-related brain activity. A 2001 paper found that a brief touch from a stranger can increase cooperation.

Research across five European cultures published in 2015 found that the area of the body you’ll let someone touch maps almost directly onto the strength of your emotional bond with them. There’s plenty of cultural variation though. Brits are famously more guarded about casual contact than other Europeans, and touch between men in many western contexts carries particular social weight.

Perhaps most strikingly, touch before competition makes a difference. A study of negotiators found that pairs who shook hands before bargaining cooperated more, lied less and reached better joint outcomes, even in situations where cooperation came at a personal cost. A handshake may signal something important about intent before a word is even spoken.

But physical contact matters even during competition. A 2010 study of all 30 teams in the US National Basketball Association during the 2008-09 season found that the teams who touched more during games early in the season, through fist bumps, hugs and high fives, performed better and played more cooperatively later. This held even after controlling for player salaries and preseason expectations. In another 2024 study of women’s college basketball, players who received more physical contact from teammates after missing their first free throw were more likely to score on the second.

We see the same thing in genuinely high-stakes situations too. Research analysing street conflicts using CCTV found that witnessing a fight increased anxiety in bystanders. But, those who then engaged in physical contact with others showed reduced anxiety afterwards. A separate study of consolation after street robberies found that the way bystanders approached and touched victims closely mirrored the post-conflict consolation we observe in chimpanzees.

Humans, bonobos and chimpanzees all use reassuring touch but our evolutionary lineages split over 6 million years ago. The simplest explanation is that reassuring touch predates all three of us, and is certainly far older than our own species. So let’s not forget that we hold within us powerful and ancient behaviour that can help us manage our social worlds and maintain peace.

Jake Brooker receives funding from Templeton World Charity Foundation (Diverse Intelligences Initiative) and NWO Talent Programme.

Zanna Clay has received funding from Templeton World Charity Foundation (Diverse Intelligences Initiative) for this work.

The defence investment plan sets out the UK government’s funding choices for the British armed forces. Over a year late, it allocates an additional £15 billion to the ministry of defence.

Its priorities are the nuclear deterrent and submarine programmes, a sixth generation fighter jet and an expansion of autonomous systems and guided weapons.

Across land, sea and air, the defence investment plan points towards a force that depends more on space-based systems, not less. So it is disappointing that the new plan is unclear on its long-term plan for space.

Both the 2025 strategic defence review and the 2026 defence investment plan tend to speak of space-based capabilities in the broadest terms, providing no clear sense of direction in many areas.

The newest planp is following the tradition of past defence reviews by approaching space as a list-making exercise, where generic capability categories are listed as desirable and important but no prioritisation is made. The DIP does not offer any rationale for which specific capabilities the UK military should develop first.

Some space-based capabilities remain sovereign – operationally controlled by the UK. Others are acquired from external providers: allied countries such as the US, or commercial entities.

Limited defence budgets mean that many space services rely on a mixture of sovereign and external systems. These include satellite communications, space control (ensuring freedom of action in space and denying it to others) and intelligence, surveillance and reconnaissance. This is a broad category and includes many different kinds of imagery and other data gathered from spy satellites.

Political leaders have a responsibility to explain the trade-offs and why they are made. But the defence investment plan does not explain which specific space services the UK armed forces will demand from its allies and from commercial third parties, or how the rest of the force will operate within those constraints.

High-intensity warfare

The headline treatment of space – across one and a half pages – appears positive. Space is recognised as “critical national infrastructure” by the UK government, in line with years of established policy.

Space infrastructure is seen in the defence investment plan as “the central nervous system of modern, high-intensity warfare”. The defence investment plan allocates £3.2 billion to space capabilities up to 2030 and promises at least £9 billion more between 2030 and 2035.

But most near-term spending remains concentrated in satellite communications, with £2.3 billion allocated to the Skynet satellite system, which provides secure communications to the British military. Delayed by two years, the Skynet 6A satellite is scheduled for launch in 2027.

Plans were underway for Skynet satellite systems that would cover the wideband and narrowband frequency ranges respectively. The narrowband system has now been cancelled, but the defence investment plan does not explain the operational consequences of this move, or what will replace it.

The planned Deep Space Advanced Radar Capability (Darc), along with Skynet, is one of the few specific space related programmes named in the plan. It will provide radar coverage of the geostationary belt, a region of space where satellites orbit at the exact speed of the planet’s rotation.

Darc will monitor satellites, space debris and potential space-based threats from other nations. Based in Wales, Darc will be networked with similar installations in the United States and Australia to provide global coverage.

A worrying omission in the defence investment plan is the relationship between its £880m allocation for intelligence, surveillance and reconnaissance and space control and the existing Istari programme. Istari is described as a £970 million multi-satellite programme to support global surveillance and intelligence for military operations.

One of the satellites under the Istari programme, Tyche, launched on August 16 2024. Tyche is the ministry of defence’s first sovereign optical imagery satellite. Another Istari satellite programme, called Oberon, is expected to provide two synthetic aperture radar satellites for day and night, all-weather 3D radar imagery.

Yet the defence investment plan does not clarify whether the £880 million allocated for intelligence, surveillance and reconnaissance in the plan continues, replaces, or accelerates specific capability types within Istari – or whether it will go to services acquired from external providers.

New or old?

It remains unclear how much of the £3.2 billion for space represents new spending or restates earlier commitments in the 2021 integrated review, the 2021 national space strategy, the 2022 defence space strategy and the 2023 national space strategy in action.

The UK requires a much clearer account of what space services its future force assumes responsibility for, which of those services it must own or control, and which it is willing to access through allies or its commercial providers.

Much of the defence investment plan’s wider logic amounts to a rediscovered faith in old 1980s-era reconnaissance-strike battle doctrines. It prioritises finding and neutralising the enemy’s command and control, logistics, and reconnaissance capabilities using long-range precise weaponry.

The issue is not that this model is the wrong way to organise combat forces, but that it is highly dependent on space infrastructure. This will require multiple integrated technologies that are able to convert raw operational data into actionable intelligence, not least from space.

The defence investment plan recognises this in rhetoric but does not explain how the UK will secure access to the required space infrastructure.

The consequence is that British military operations will continue to depend on a “central nervous system” that is not sovereign. That places greater weight on UK diplomacy, foreign policy, and contracting mechanisms to ensure continued access to US, European, and transnational commercial space infrastructure.

More spending on space is not always the answer given other pressing needs. Rather, detail is lacking about what the UK military intends to invest in with its existing funding. It is also unclear whether UK government understands the strategic consequences of Britain’s reliance on allies and commercial third parties for essential military space infrastructure.

The defence investment plan was a moment in which the government could have converted five years of strategy documents into a modestly funded order of clear, specific capability development priorities. The government declined to do so.

Until it can, the £3.2 billion buys continuity rather than direction: a communications programme, a new ground radar, a small down payment on divergent types of intelligence, surveillance and reconnaissance, and another list. Admitting the limitations would set a more grounded foundation for public and professional debate on British defence policy in the space age.

The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

It may seem like we are on the verge of discovering alien life. In 2025, a press release stated that we have the “strongest hints yet” of extraterrestrial life on the exoplanet K2-18b. And when talking about a collected sample from a rock named “Cheyava Falls” on Mars, Nasa Administrator Sean Duffy said this was the “closest we have ever come” to discovering life on the red planet.

Such moments capture the imagination. But they also raise an important question: what do the majority of scientists actually think?

Surprisingly, we usually don’t know. When a scientific controversy or breakthrough dominates headlines, press officers and journalists often quote a handful of experts. These views may be insightful, but they rarely tell us what the wider scientific community thinks. And yet public discussions frequently rely on phrases such as “the science says” or “scientists believe”, as if there were a clear and measurable answer.

In reality, systematic evidence about scientific opinion is often missing. My colleagues and I recently tried to change that in the domain of astrobiology. Shortly after the two major announcements of possible extraterrestrial life in 2025, we surveyed astrobiologists to understand how expert judgment was distributed across the field.

The first case concerned the exoplanet K2-18b. In April 2025, researchers reported possible traces of molecules called dimethyl sulfide and/or dimethyl disulfide. On Earth, these are associated with biological activity. Media coverage was extensive, with many reports framing the finding as an extraordinary advance in the search for alien life.

The second case came in September, when Nasa announced that Cheyava Falls appeared to preserve a potential biosignature – so-called “leopard spots” which are mineral rings that on Earth are often formed by microbial activity. Again, headlines, and Nasa officials themselves, suggested something momentous.

What scientists actually thought

We surveyed hundreds of astrobiologists from across the global research community, within days of each announcement. We asked a simple question: did scientists think extraterrestrial life had probably been found?

The results revealed a rather cautious picture. For K2-18b, only 6.6% of surveyed astrobiologists agreed that scientists had probably found extraterrestrial life. Nearly two-thirds disagreed, while 28.0% remained neutral. For the Mars case, confidence was higher but still cautious: 15.1% agreed, disagreement fell to 44.6% and neutrality rose to 40.3%.

Looking only at agreement and disagreement, however, misses an important part of the story. The proportion of astrobiologists who strongly disagreed fell dramatically, from 35.1% in the K2-18b case to just 11.1% for Mars. Much of the movement was therefore not from rejection to endorsement, but from strong rejection towards more tentative positions.

In other words, expert opinion moved in structured ways. The shift from K2-18b to Mars was not a simple movement from “no” to “yes”. Instead, the community became more open to the possibility without embracing it outright.

One possible reason is that the two cases involved different kinds of evidence. The K2-18b claim relied on possible atmospheric signatures detected from across interstellar distances, whereas the Martian case concerned a rock that could be studied directly and in much greater detail. At the same time, astrobiologists have long been aware that apparently lifelike features can sometimes arise through non-biological processes. Often, the challenge is not imagining how life could produce a signal, but understanding all the ways nature might produce something similar without life.

Scientific opinion is rarely binary. Public discussion often treats science as though communities either agree or disagree. But the distribution of opinion matters too. Strong agreement, agreement, neutrality, disagreement and strong disagreement can each tell us something different about how a scientific community is responding to a claim.

A large neutral response can indicate several things. Scientists may judge the evidence genuinely inconclusive. They may hold an intermediate level of confidence. Or they may regard a claim as too speculative to endorse or reject decisively. Likewise, movement from strong disagreement towards ordinary disagreement may signal a softening of attitudes even when overall disagreement remains high. Treating scientific opinion as simply “for” or “against” risks flattening these important distinctions.

Beyond extraterrestrial life

The broader lesson extends well beyond extraterrestrial life. In areas such as climate science, pandemics, artificial intelligence or medical research, public conversations frequently invoke scientific consensus.

Sometimes strong agreement genuinely exists. Sometimes it does not. But we often lack systematic ways of measuring what scientists actually think, especially where evidence is emerging or uncertainty remains substantial. Instead, discussions rely heavily on selective quotation, vocal individuals or assumptions about community views.

Efforts to do this more systematically are beginning to emerge. At Durham University, our research group, C-Scope (the Centre for Scientific Community Opinion Polling and Evaluation), studies how expert opinion is distributed and how it changes over time. We are not trying to replace evidence with polling, nor to treat majority opinion as truth. Our aim is to better understand how scientific communities respond to uncertainty.

Scientific knowledge advances through uncertainty, disagreement and gradual revision. If public discussion, and perhaps political will, increasingly turns on claims about what scientists think, we should make more effort to find out.

Peter Vickers does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

For the last few years, I’ve been seconded to assist the Catholic Church’s unprecedented global grassroots listening initiative. Just as that process drew to a close, I received a surprise request: would I help Pope Leo XIV launch his first social encyclical, focused on what it means to be human in a time of artificial intelligence?

It is difficult to think of a more important theme right now than the impact of digital technologies, AI and robotics on every level of our social interactions and structures.

The Vatican has addressed technological questions before. My research includes the social teaching of popes since 1891, starting with Pope Leo XIII’s influential text Rerum Novarum (Of New Things), which addressed the impact of the industrial revolution on working people (and which this new text commemorates). A range of previous letters have addressed both the opportunities and dangers of technology.

Of course, the Vatican does have a chequered history with regard to theological reflection on scientific and medical developments. Over the past decade, it has been pursuing focused and, in my view, productive conversations with the AI tech sector through initiatives such as the Minerva Dialogues – a series of closed-door conferences with leading figures from both worlds. In this sense, the concern with AI does not spring from nowhere.

Nonetheless, Magnifica Humanitas (Magnificent Humanity) was a landmark moment: a papal text addressing AI as its central focus for the first time, launched by a pope in person – this does not usually happen – in the presence of the very industry it sought to critique. The encyclical panel on which I sat also included Chris Olah, co-founder of the AI tech firm Anthropic.

All of this meant a much higher level of media and public interest. In the run-up to launch, questions about the make-up of the panel and how equipped a pope is to comment on AI showed me this text would be controversial. And that’s OK.

The job of the text is both to offer the stimulus of a particular tradition – Catholic social teaching – and to encourage debate among people with a variety of views about what makes for a common good use of AI technologies. Our task as a panel was to explore both of these realities.

Not anti-technology but pro-human

The Vatican was unconcerned about the encyclical’s lack of neutrality because it declares its hand transparently – and does not believe the tech sector operates with a neutral mindset either.

The inclusion of Anthropic on the panel was welcomed by some as a sign of serious engagement with the sector on these issues. For others, it showed a risk of naïvety about the Vatican’s corporate capture, or of privileging the voices of capital.

The document calls for a movement out of the silos of private boardrooms where the morality (and profits) of new technologies is decided by the few, into a public space of transparency, participation, common benefit and shared power – if that is possible.

Olah did at least note that the tech sector requires exactly the kind of conversation this text promotes: a public, shared conversation in which the shape of our working, educational, political and social lives are not determined by a few wealthy individuals.

The text is neither anti-technology nor anti-industry. It is pro-human, pro-social and resistant to false religious claims that AI will, in itself, save us. It resists the idea that human limits are things to be despised and overcome with models of perfected or eternal bodies or minds.

It stresses that AI should enhance the human capacity for finite, embodied relationships, for meaningful work as part of a dignified life, and for the human person to be recognised as an end – not a tool of utility, power or profit.

Technology is as old as humanity. It is part of how we shape and steward our world. It preserves and fosters our survival, and the social lives that give us meaning. Pope Leo was clear: what matters are the ends to which these new AI technologies are set, and their relationship with the Earth’s natural resources.

Reshaping the idea of being human

The Vatican has issued previous texts comparing human and artificial intelligence, as well as a separate text critiquing trans- and post-humanisms. The added dimension in Leo’s first social encyclical is to ask questions about how technologies are reshaping the very idea of being human – rescripting work, education, politics and warfare – and how they are enacting and enmeshed in new cultures of dominating power.

The text interrogates freedom and flourishing – two categories central to Enlightenment thought.

Within the church, there are theologians who are engaged optimists regarding the possibility of AI technologies, and those who are more guarded. There are also some who might be characterised as “radical pessimists” – an honourable tradition to be distinguished from the merely cynical.

The new text draws from each of these perspectives, while remaining closest to a prudential middle. It names the risk of new dependencies, exclusions, manipulations and inequalities. Any positive and hopeful account of such new tech must be able to face and respond to these realities.

Above all, this text marks a new phase in the papacy’s public (rather than closed-door) involvement in debates about AI technology. Its invitation is for a social dialogue on many levels across many groups, sectors and stakeholders.

My experience is that views on these matters are lively and fiercely contested. But above all, they are urgent.

Anna Rowlands is a member of the Dicastery for Integral Human Development at the Vatican. This is a governance role. She has also served as an advisor to the Vatican in various capacities for the last five years.