Preparing to meet Hassan Arero, the keeper of anthropology at the Horniman Museum, to talk to him about his work and his background, is a bit like doing my own anthropological study of him.

Arero is celebrating his tenth year in museums. Three of these have been spent at the Horniman; his arrival coinciding with the centenary development in 2002.

Frederick Horniman's world collections, including natural history and musical instruments, were bequeathed to the people of London in 1901. Applauded as much for its diverse collections as for its interpretation of them, the Horniman is a mini-British Museum nestling in Forest Hill, a quiet corner of south-east London.

Arero is a long way from home. Born in Kenya in 1970, he came to Britain, first to the Sainsbury Research Centre at the University of East Anglia for his masters in the Advanced Arts of Africa, Oceania and the Americas and following that up with a PhD in social anthropology.

With the 80,000 objects of the Horniman's World Cultures collection in his care, Arero has his pick to jump-start investigations into historical and contemporary accounts of the people and regions of the world.

Right now, he is curating an exhibition exploring the link between Amazonian culture and Caribbean identity to open in October at the Horniman, and which will run for a year. Amazon to Caribbean will be the first major temporary exhibition in the new Horniman, Arero says.

He chose this theme mainly because of the Caribbean population in Forest Hill and surrounding areas in south London whose culture is 'largely left out' in the displays.

The African and Pacific collections are already on display. The museum has a substantial collection of materials from the indigenous people of Guyana, Venezuela and Brazil where he began his research.

In 2003, Arero made two trips to Guyana to study and live among the Wai Wai, who reside both in Guyana and Brazil. The exhibition is his attempt to reveal the cultural links between the early Amazonian cultures and today's Caribbean identity.

He wanted to move away from the over-researched area of Brazil to look into the depths of the Amazon in southern Guyana, including the Amerindian-inhabited coastal areas of the country.

What he found was a renewed interest in their own Arawak culture among the Amerindians themselves. This was following the denigration of their culture by the Catholic missionaries.

He also found that contemporary artists in Guyana and on Caribbean islands are heavily influenced by Amerindians such as the Wai Wai in the art that they produce.

Arero shows me a model of the exhibition in his office. The plan is an ambitious showcase of the artefacts, archaeology, bought pieces from Guyana and contemporary art which will link to Caribbean Identities, the museum's year-long outreach project with the local Caribbean community.

Anthropology appears to fit Arero like a glove; his interest in people started at an early age. Born Gurach ('black'), Wario (his father's name, given to those born at a time of relaxation), Arero (a traditional name belonging to his particular ethnic group), he was given the name Hassan at the age of ten. From the Borana ethnic group, he grew up in northern Kenya living, like his people, as a nomad.

He says he was always interested in language and can today speak more than three Kenyan languages. His first passion was acting, which he did at primary school. At secondary school, which he describes as a 'diluted set up of the British boarding-school system', he began to write plays.

Later, at university, he joined a travelling theatre where he would take plays to market places and perform the likes of Romeo and Juliet in schools. While still in Kenya he worked as an actor on various British television productions, notably a documentary with the renowned director Peter Kosminsky. His first rent was paid with his actor's wages.

So Arero's ability to fit and adapt to new ways in a short space of time, comes as no surprise. He lived, ate and hunted with the Wai Wai for three weeks.

Had he refused the turtle meat offered him it would have been seen as declining their welcome. He mucked in with the men and women, shifting sand and helping to build a women's craft centre.

Fitting in didn't happen so easily when he left northern Kenya for coastal Mombassa at nine years old and was often the only Borana boy in class. The pastoral cultures of Kenya, such as the Borana and the Masai, are often stereotyped as 'lazy, uneducated, wild and untamed', says Arero.

This is a throwback to the days of imperialism when the British ignored the northern civilisations in favour of the agricultural communities. It was the latter regions where the infrastructure - the roads, the railways, the schools - were built.

But it was his experiences during the 1970s that heralded his interest in ethnicity. It was a time of extreme nationalism, especially in his region where there was suspicion that the north wanted to secede and join Somalia.

There were compulsory meetings with officials where northerners were expected to demonstrate allegiance to the Kenyan nation. When tribal inter-marriages took place, the courts would decide on which family member would be allowed to bury their dead.

'One of the major things I grew up not understanding was the questions around ethnicity. I just couldn't connect with people who thought along ethnic lines,' he says. He excelled in history, languages and social sciences at school and opted for law, anthropology or literature at the University of Nairobi.

Anthropology was chosen for him by the university, and he was the only one from his school who went on to study the discipline. A report by a former anthropology teacher calling for northerners to be taught how to be Kenyans, spurred him on to set things straight.

'I have a problem with the mentality that people need to be taught to fit within an identity,' he says passionately. 'These people forget that boundaries were set up and that cultures and people's contacts defy boundaries and however much you school them, they will never fit in to your sense of nationalism.'

He describes the study of his own people, the Borana, as 'a one-man journey'. Very little was written about the Borana and what there was came mainly out of Manchester University. He says he had to be wary not to be drawn into clan and cultural issues. 'You have to be careful to stand outside and be a researcher.'

While studying for his postgraduate degrees in Norwich, he also worked at the National Museums of Kenya where he was instrumental in implementing the standards of the African Council of Museums (Africom) across the museum and taking them out to regional museum curators.

He then became the head of ethnography at the Museums of Kenya and spent two years in that role. At the end of the PhD, he asked himself what he needed to do. The answer came back: 'I needed international exposure.'

As well as a fascination with other African cultures, he also wanted to work with collections from the Pacific and the Americas. Britain, he says, was the place for the wider picture. He says the Horniman's presentation of the World Cultures gallery agreed with his own view of defying boundaries that people set for cultures.

Arero eventually plans to return to Africa, most likely Kenya, to set up a community museum and teach history. He has a long-term ambition to explore the untouched archaeological sites in northern Kenya.

But he is coy about revealing any ambitions in Britain, though he has stepped up his profile with a recent appointment as deputy chair of the UK branch of the Inter-national Council of Museums (Icom UK.)

As to representations of Africa in Britain, he says the key is for museums to focus more on contemporary presentations of African cultures. 'My Africa is different from my grandfather's. We watched British television and lived in urban centres. Where is that Africa in museums?' he asks. 'We need to see Africa as a child that has grown up.'

Perhaps it is to the contemporary artist that we should now look. Arero is not impressed with the romanticised stories of Africa that are often reeled out. Contemporary Africa, he believes, will help us understand the old Africa.

But then he muses: 'Once every person's world is reflected in museums, then the business of museums will be finished.' He says the predominately London-based Africa 05 events have helped in showing contemporary Africa - particularly the Africa Remix exhibition at the Hayward Gallery.

'It raised questions for people of their perceptions of Africa. It showed Africa as a diverse continent.' But he acknowledges that the West still hasn't fully accepted the old Africa.

It is unforgivable, he says, that Egypt has been shunted off to Arabia as a place separate to Africa, and that the continents of other great civilisation are contested. 'Benin is not Atlantis. Benin is Benin, and it is in Africa. We have to accept this.'