"I want to create soul," Professor Hiroshi Ishiguro of Osaka University tells me at a dinner hosted by the consul of Japan in Cape Town, Yumiko Fujiwara. Ishiguro sounds like a mad professor but he isn't. He is a world leader in robotics.

The persistent question he can't answer, which he says makes him "always unhappy", is: "What is a human?"

By creating androids he is hoping to find out.

Apart from genetic taxonomy (a mere 1% difference from chimpanzees), our attempts to define what differentiates us from other creatures keeps failing to prove absolute: the ability to make tools, to dream and imagine, to grieve, to develop language, even to have a spiritual life.

For orthodox Christians, only humans have a transcendental soul influenced by a greater metaphysical power. This belief probably underlies why, unlike in Asia, there has been more resistance to cloning and why some in the West react to the notion of developing androids with fear and disgust, conjuring up the dystopia of the Blade Runner film.

But in Japan the dominant religion, Shintoism, is animist. Perhaps this is why they seem to have an unusual affinity for everything from Hello Kitty products to droids.

Ishiguro is famous for his geminoids, copies of actual people, like Madame Tussauds waxworks, except his are silicon-skinned robots that talk, move, make eye contact and are programmed with artificial intelligence.

At a lecture demonstration last week, hosted by Professor Anton Basson of the faculty of engineering at Stellenbosch University, Ishiguro showed off Robovie-X, produced by his venture capital firm VStone. This bipedal bot walks upright, plays soccer, does a 360° cartwheel and somersaults off the metre-high table. (This last kamikaze movement was unplanned.)

Subconscious movements

We see footage of Honda's astonishing Asimo robot delivering a tray of drinks (cafés run by such cute humanoids are envisioned for Tokyo), a geminoid of a traditional comic storyteller performing in Japan (the human version is a national treasure, Katsura Beicho, aged 86) and a shop-window mannequin programmed with 65 human states of emotion (GeminoidF at one point had 12000 followers on Twitter). In one experiment, an Actroid prayed in a cathedral, eyes on the crucifix. To make the androids more life-like some are programmed with subconscious movements.

Last month, while Ishiguro was in Europe, his geminoid gave four lectures in Japan on his behalf. Its computer converts his voice into simulated lip movements.

Ishiguro told his students they could kick "him" because it was only a robot but they recoiled at the idea. Unlike a Skype conference, the android has a tangible presence, a physical projection of oneself.

Ishiguro relates how once, when someone poked a finger into the geminoid's cheek he felt it, and when someone kissed its head he withdrew. A strong transference was at work.

Neurologists have identified mirror neurons in our brains that fire not only when we act but also when we observe the same action in others. Something similar may be happening with the geminoids.

Ishiguro explains how prosthetic limbs become part of an amputee. Consider too people who have had hand transplants.

Science has rather belatedly started to recognise embodied cognition, the discovery that our mind is partly body dependent. And, if neuroscientist John Cryan is correct, bacteria in our gut affect our behaviour and personality in surprising ways.

Maximising the imagination

To develop android artificial intelligence, Ishiguro says, it must possess a body. His Elfoids are mobile phones shaped like … well, imagine a human tadpole. The elderly, who struggle with smart phones, feel less lonely after a call on an Elfoid, he says. Humans are innately programmed to respond to the human form far better than speaking into a black box.

A video of an old-age home in Denmark shows the residents hugging Telenoids (big versions of Elfoids). Minimal features and blunted limbs have the converse effect of maximising the imagination. For many elderly people, real humans are a bit of a trial.

After a little chatting, most people start to treat droids as other beings.

Cultural acceptance of social robots is part of Japan's economic plan. A decade ago Japan produced more than 70% of the world's industrial robots, but China and Korea have made significant inroads.

The Japanese government's vision, Innovation 25, introduced in 2007, set aside $26-billion to shift from industrial to world leader in domestic robots.

Pursuits such as Ishiguro's will also virtuously feed back to industrial robots. Seeing the mechanical lattice of the android at work with the skin off is an extraordinary sight.

Ironically, as Ishiguro develops bodies for androids, people seem to be using theirs less. The last time I misplaced my iPhone, it felt as if I'd had a stroke – disorientated, un-able to remember appointments or communicate.

Productivity

"Won't people become machines long before we can create machines to be like people?" I ask Ishiguro.

"We must pursue both," he replies.

It is hoped domestic robots will boost productivity, freeing women from domestic chores and even child-care. In a country notorious for its xenophobia, a made-in-Japan robot may prove preferable to a foreign au pair.

Japan has a fertility rate crisis. Surveys suggest young Japanese couples far prefer pets to children. And, Botox aside, men might end up preferring androids to women. The blow-up doll is long gone; creepily lifelike "love dolls", originally developed in Japan for disabled men, have morphed into a giant sex robot industry.

Speaking of love, which Ishiguro suggests he doubts exists, I ask: "Will robots ever possess consciousness?"

"Yes," he replies without hesitation. "Why not?"

Autonomy

I think of CJ Jung apologising to his pots and pans on a clumsy day, scientologist Tom Cruise shouting at an ashtray for hours to somehow command it. Perhaps androids will or do have some kind of consciousness.

"If the android develops consciousness, will the next step be autonomy?"

"Yes," says Ishiguro. "If you are autonomous, the android will be as well. [But] what is your definition? Are you autonomous? How do you know?"

"What if US military drones are given autonomous decision powers to kill?"

Ishiguro shrugs. "They are crazy for killing people. We [in Japan] never think about that. We don't like to kill people."