The way people behave in Meet the Humans - a new BBC series that puts people's emotions and everyday behaviour under the spotlight - has more in common with a troop of mountain gorillas in Planet Earth than you would think.
When an alpha male pulls up late for a high-school reunion in a flashy blue car, the man who has already established dominance stands taller while the other men flinch, fidget and joke, keeping a wary eye on this rival. The women's reactions are less overt but they also pay attention.
Meet the Humans takes place in an English country manor like Downton Abbey and the volunteers who come forward in each episode think they are taking part in a TV reality show.
What they don't know is that the writer and presenter, Dr Michael Mosley, is watching their every move from behind the scenes flanked by psychologists and neuroscientists who interpret what they are doing.It's as if he is in an animal hide and the people are predators and prey interacting at a waterhole.
Every episode is designed to trigger basic human emotions like fear, lust and competition.
Mosley says: "We wanted to see if people would act in predictable ways and I loved it that often they did not behave the way we predicted. They also sometimes did exactly what we would expect. In one scene we have identical twins rowing and as soon as we get a pretty girl to watch, they start to show off. Their heart rates go up, without them even being aware they are doing this."
Some findings supported existing research - for example, after priming the brain with positive words like "vibrant" and "active", nearly all the volunteers walked faster.
This test was done in the first episode, set up like a school reunion, which focused on the "ageing animal". After donning school uniforms, some of the women were swinging their arms like kids and bouncing around.
Mosley says: "The participants on that weekend last saw each other when they were 16 years old and now they are 49 or 50. We wanted to see if we can turn back time and get them to relive their experiences, even including the school bully, and we planted false memories."
The producers did this by including a man who had never attended their school and trying to convince the group, with the aid of a falsified year book, that he had been at the school but they had simply forgotten him.In that episode (which aired this week) Mosley also tested whether putting people back into a schoolroom context - they wore uniforms, took part in a physical education class and quiz, there was even a disco - would make them act more youthfully.
Physical prompts like the feel of uniforms, the smell of school dinners and other cues were used to evoke their student memories and that feeling of being young.
By the end of the weekend everyone but the imposter had lower blood pressure and a few of them had more spring in their step. Mosley was surprised by how much most of the participants in each episode enjoyed their experiences, even after finding out that they had been unwitting guinea pigs.
"It was important they did not know the purpose [of each episode] so we used subterfuge. But people genuinely loved taking part."
In the school reunion, for example, the woman who started off awkwardly as a self-declared introvert left feeling more positive - in contrast to the school bully, who left seeming more reflective.
Meet the Humans is contrived, of course, but it has a winning combination of drama and comedy, supported by the science of the human animal and our ability to connect to the subjects.
As the surveillance cameras zoom onto some unsuspecting person, you can imagine how you would feel. Or what you would do. 
WHY WATCH
"Meet the Humans" harnesses sophisticated technology to analyse human behaviour, an advantage we don't have in everyday life.
Every volunteer wears a heart-rate monitor and microphone, which makes it possible to detect any discrepancies between what they say and what they really feel.
In the singles' flirting weekend, for example, participants might be acting calm yet Mosley and his team can see their heart rates are racing. They analyse the physiology and explain what impact their hormones are having on the participants.
"We have the technology to peel back the layers," says Mosley. "The question we want to answer is: what is going on between their brains and their bodies?"
'Meet the Humans' (Mondays at 8.30pm) is the first in a special series called 'Being Human' which started this week on BBC Earth (DStv Channel 184)...