BACK in the day when the Bay City Rollers and The Jackson Five were pinned to the walls of girls' bedrooms, and when heavyweight world champion Muhammad Ali thrilled and inspired the nation on the Parkinson show - my brother and I set out on an adventure.

Sporting shoulder-width afros, high-waisted trousers and brightly coloured, butterfly-collared shirts tipped with gold stars, we sneaked out with our bikes and headed south, deep south.

From our run-down tenement block in Glasgow's Partick we were headed for Priesthill, a large 1950s-built housing estate where my grandmother lived. To the first inhabitants, moved there from the tenement slums of Govan, Priesthill – with its wide boulevards, green open spaces and tree-lined avenues – would have seemed like Shangri-La. But now, in the early 1970s, it had fallen into neglect. Packs of dogs roamed the streets, the trees were mostly vandalised and the greenery had turned to bare hard earth.

I was only seven or eight at the time and couldn't keep up with my older brother so for the last mile we wheeled our bikes along the bleak pavements. After a block or so I noticed we were being followed by a couple of teenagers. Further and the two had become six. By the time we reached my grandmother's house a sizeable crowd had spilled from the mud-coloured houses: teenagers, toddlers, women with scarves and rollers. Whispering, staring, bewitched.

We quickly made our way up the path and thumped on the door. As we waited, a small boy with a shaven head broke from the crowd and tapped me on the shoulder. "Wanna fight?" he asked, pointing to the overgrown lawn ringed by onlookers. His eyes were full of excitement, happiness and the deepest respect. It was in his mind, perhaps, the closest he had ever come to meeting Muhammad Ali.

The Priesthill adventure is one of the earliest memories I have centred on the colour of my skin. Later memories have an altogether different flavour. As a teenager I had fathers warning me off their daughters or apologising for not having any watermelon in when I called round for dinner. On the way to school, I'd be stopped by scaffolders who would bend down to hiss: "Black bastard." I had a teacher call me "wog" in front of a full class.

Then there was the 1977 television drama Roots, charting the history of an African-American family from slavery to emancipation. For eight weeks while the series was being aired, the schoolyard became an arena of vicious verbal combat. Most of my schoolmates understood the programme's intention: to confront people – black and white – with the brutal reality of their shared history, hoping the empathy thus engendered would inspire changes in our behaviour. But many of the kids I went to school with lived in grinding poverty. Overcrowding, alcoholism, and violence in the home and on the streets were everyday realities and yet the world looked away. I cannot condemn them for resisting the notion there was something special about black pain. For those others who got in on the game it was similar to the phenomenon I'd experienced in Priesthill, but shorn of any respect.

That was back in the day. But now? Neville Lawrence, the father of murdered teenager Stephen Lawrence, says he fears for his grandchildren on the streets of London; Diane Abbott causes offence when she says white people love playing divide and rule; and two conflicting reports reignite fears that jobs for Brits are under threat from non-EU immigration.

In America, a country with a quite different legacy of race than Britain's, the wound has been reopened. More than four decades after the fight against segregation and disenfranchisement in the 1960s, Rolling Stone writer Touré has published a book entitled Who's Afraid Of Post-Blackness? This account of what it is like to be young, black and middle-class in contemporary America is confronting white Americans with the reality of what he calls the "fog of racism": a hidden racism that keeps the doors to advancement and full participation in society closed. But what about here and now? Is Scotland racist?

I'm a business writer. I write about the economy, energy and the environment and have steered clear of the subject of race, as well as hip hop and boxing - deliberately. But to my knowledge I am the only black journalist in Scotland, the only African-Scot journalist. Some people assume Scotland has its Barnett-quotient of Afro-Caribbeans but, according to the 2001 census, there were 8025 black people in Scotland, 0.16% of the total population. This compares to around 2% across the UK as a whole. By contrast, there were 55,007 Pakistanis, Indians, Bangladeshi and other South Asians (making up 1.09% of the Scottish population). There were also 16,310 Chinese: 0.32% of the population, or more than twice the estimated number of Afro-Caribbeans.

For black people in Scotland, therefore, with no Brixton or Toxteth to look to, there is no discernible black community. We Afro-Caribbeans, dotted around the country, are little islands of ethnic isolation.

That is not to say race is not an issue. Since the Macpherson Inquiry into the handling of the Stephen Lawrence murder investigation, police have kept records of racist incidents, defined as "any incident which is perceived to be racist by the victim or any other person". In 2009-10, 663 recorded incidents involved black victims, and 127 concerned people of Chinese ethnic origin. By far the greatest number, 2571 cases accounting for around 48% of victims, were of Asian origin. From 2004-05 to 2009-10, racist incidents in Scotland increased by 9% and around 96% of perpetrators were white. But perhaps the most surprising statistic reveals 1153 white British people were the victims of racist crime in 2009-10 in Scotland, and 860 of the perpetrators were other white people, whether Scottish, Welsh, Northern Irish or English.

Years ago I moved to a small rural community on the west coast of Scotland. By then I'd become accustomed to arriving in places where locals had seldom been a black face before. I'd nod and get chatting and soon enough the novelty would wear off.

Every so often I'd board the bus and head to Oban for a bit of nightlife. Once, I found myself sitting next to the local postmaster. A former coal miner from the north of England, he had invested his redundancy cheque in the local post office and general store, thus rescuing a local business once earmarked for closure. He and his wife took great pains to accommodate the locals: "If they knock on my door in the middle of the night looking for drink, I oblige." After seven years in the town, however, he had decided to sell up. His wife was miserable because they had failed to establish any friendships in the town. "They don't like outsiders," he said, his eyes full of resignation, weariness and a soul-deep disappointment.

My own experience, after three months in the town, had been totallly different. The clearly perceptible difference between us was that I spoke with a Glasgow accent. In truth, the concept of race has never sat easily with me. Although I'm black my mother was white and my father was African. I am mixed race, but black. As a teenager I queried the notion that certain people had a physiological reaction to the colour of another person's skin: a reaction so strong it provoked murderous violence. The more I delved the less convinced I became the concept of race had any validity. Race is a concept manufactured by 18th and 19th-century intellectuals who traversed the globe, obsessively categorising everything that moved.

To me, it seemed race veiled some deeper phenomenon. After self and family there is tribe. The tribal instinct is rooted in the gut and not the head, but it sits uneasily with a Western sensibility focused on science and progress. Tribalism solves the paradox of the differing reactions of locals in that small rural Scottish town towards me and the postmaster. It casts light on the curious white-on-white racism recorded annually in Scotland.

But tribalism does not explain the murder of Stephen Lawrence. I would argue that tribalism provided an excuse for murderous instincts, and what gives rise to such instincts is a deeper set of problems with roots perhaps in the neglected suffering so many children endure.

Is Scotland racist? I'm not sure the question means very much. Ask me if Scotland is tribal, however, and I'd say most definitely. Scotland is a thick weave of competing tribal networks, some many centuries old, and I traverse them as best I can with an array of honorary memberships.

In Touré's book, "post-blackness" refers, among other things, to the relatively recent convention of describing people in terms of their ethnic origin. Gone is black, in are African-Americans, who take their place among the Polish-Americans, Irish-Americans and Korean-Americans in the pantheon of American tribes that make a nation.

But there is also an explicit and intense individualism, which shuns tribal or racial allegiance. Touré's interviewees expect social advancement should be based on merit when, in reality, this ideal is elusive, because even if blatant prejudice has receded, a "fog of racism" remains. "There is no-one calling you a n***er to your face," writes Touré. "There's no sign saying you can't enter this building. It's subtle, it's blurred, but more often than not, it's there."

This form of hidden discrimination is perhaps the most difficult to deal with. Nothing is said. There is no violence. But you know it's there - perhaps in a look. For that reason it is also the most difficult to talk about. It nags at you like an ulcer and you learn to bear the discomfort. You carry on. Do I suffer this fog of racism today? I certainly suffer the suspicion that I am a victim. The nagging doubt, for example, that I am not paid the same amount for an article that would be paid a white counterpart. This fog has always existed. In work, on the street and even in romance ... Does she want me for me? Or for my perceived exoticism?

The foggy racism that Touré describes used to be called middle-class racism. The idea was that middle-class people would never sully themselves with explicit verbal abuse or, God forbid, violence. As a student at Glasgow University in the early 1980s, me and a couple of white friends once cornered a lecturer to ask for advice. All of us had moved up to university from working-class Glasgow comprehensives straight from fifth year. Strangely, first-year courses at the university assumed all students had passed A-levels. There was a gap in our knowledge and we wanted some guidance. We presented our difficulties in turn. The lecturer, a pipe-smoking Scot who usually sported a bow tie, listened attentively then leaned towards us. "I'm sorry, but I haven't a clue what you're saying," he said and marched off.

Perhaps that lecturer was teaching us a lesson about surviving in the middle-class tribe into which we would graduate. Our accents would have to change. This brings class under the umbrella of tribe. And class prejudice is another negative aspect of tribalism. Tribe can reach further to find common cause in ethnic and class prejudice, as with the complaints of the white working class who say they are overlooked in social policy.

Scotland has changed since the 1970s. There are policies and laws designed to prevent racism, and language is controlled and policed as never before. A growing consciousness of something called "racism" has occurred, and to an extent that consciousness has led to a diminishment of its indulgence. But middle-class racism – the foggy stuff – has increased. Or is that just a nagging suspicion I'll always have to live with? It's hard to tell.

In the coming years, competition for scarce resources, be it for jobs, raw materials or even water, is set to intensify. When there is competition for resources, tribalism can lead to wider social conflict. Tribalism has its obvious dangers. But some of the tribes I have encountered, such as the GlobalScot network that seeks to help Scottish companies establish themselves abroad, are beneficial. Focused on co-operation, tribalism can be a force for good and this is where it differs so fundamentally from racism. It could be argued that the setting up of the EU reined in ancient tribal enmities. The threats from its unravelling are grave.

For Scotland, with the prospect of a heated debate over independence and the allocation of precious oil reserves, there is perhaps a complacency that whatever the outcome of any referendum, the weave of networks that reaches across our shared borders will somehow spare us coming to blows. My father came from Nigeria, where a brutal civil war was fought when Biafra sought secession. Biafra was where the oil was most abundant. What distinguishes Biafra from Scotland? Nigeria from Britain? Are people really so very different there? Has science and progress subdued our gut emotions?

As the figures attest, in Scotland white-on-white racism – if that's the right word – is a reality and we would do well to tread cautiously when we come to rally our competing tribal passions.