'What he thought was right had nothing to do with geomancy,' says Sandi. 'It was a question of how the building responded to its context. Once he knows he has the right solution he sticks to it and that's what I like.'

As with most father-son relationships, the one between Sandi and I.M. Pei, who recently celebrated his 92nd birthday, has had its moments of joy and pain. Together, they embody the truth that love between a father and a son is a rough diamond that has to be cut with a sharp tool.

'I've had my share of arguments with my father over everything from design ideas and details to preferences in art and music,' says Sandi. 'Some things, I've discovered, need to be left on the table unresolved.

'At an earlier time in my life I felt restless and frustrated by the extent to which he was managing my career and inhibiting my emergence rather than assisting it,' he says. 'In those days, I often felt suffocated and without my own identity. Today that sense has largely dissipated but, with a strong father in the same field who casts a very long shadow, it has not entirely gone away.'

There has also been the issue of taking in what each other has to say.

'My father doesn't think I'm a good listener,' says Sandi. 'I could say the same about him but at this point in his life he doesn't need to listen to me.'

Nonetheless, the two men do listen to each other, have collaborated on world-class projects (Sandi was the project architect for the Bank of China building and co-ordinated its construction) and now - thanks to Anna - are forming a deeper and more loving relationship.

The Peis are one of several Asian families who have created successful dynasties that thrive on family values, especially the relationship between father and son. The family can be a toxic swamp of neuroses - psychiatrists can point to a long list of conditions that have their roots in family relationships - or, sometimes, especially in Asia, it can be the platform for exceptional achievement.

The buildings created by the Peis are known all over the world but their reach does not exceed that of the Lee family, inventors of oyster sauce. Every year, the Lee Kum Kee company manufactures US$700 million worth of food and health products that are sold in more than 80 countries. But the path from the moment Lee Kum Sheung accidentally invented oyster sauce in 1888 (he overcooked a soup) to the peak of the global food business has been a tough one. In each of the previous three generations of Lees, a deep split opened up between siblings that almost destroyed the company and the family.

The last cataclysmic feud took place in the 1980s, when Lee Man-tat - who is still group chairman - decided to expand the company, a move that his brother opposed. The result was a schism that was never healed and caused Man-tat so much stress he fell ill. Two surgeries later, his four sons decided that action was required.

The fourth generation of Lees has gone to great lengths to develop and maintain family harmony. Every three months the Lees hold a retreat that lasts for four days. Man-tat (80), his wife, May Ling, and children, Eddy (53), Elizabeth (52), David (51), Charlie (48) and Sammy (45) gather at a hotel or golf club and work out how to strengthen themselves, their family and their business.

The most recent retreat took place last weekend, at the Hong Kong Golf Club in Fanling. A relaxed atmosphere prevailed as the meeting began. Charlie and Sammy played table tennis while May Ling made jokes about how much her husband enjoys the attention of pretty girls. It hardly seemed like a meeting of the principal players at a billion-dollar corporation but this is the way the Lee family does business. And a key aid to their relationship is the wearing of baseball caps.

'We find that it's very important for roles to be clear,' says David Lee, who is chairman of Lee Kum Kee Foods. 'If you are in the middle of a family dinner and everybody starts talking about business it can ruin the whole thing and the next generation will be alienated. And in the boardroom if somebody tries to win an argument by saying, 'I'm older, so you have to listen to me,' then everything is ruined. So we made the baseball caps.'

The caps are printed with words such as 'Chairman', 'Business', 'Family' and 'Coach' and they are worn when somebody starts to forget what role they are supposed to be playing. The idea came from a seminar in Switzerland at which a professor discussed a man who had to fire his son. The father had announced, 'Firstly, I'm your boss, you're fired' and then he switched roles and said, 'OK, now I'm your father, how can I help you?'

'I thought this separation of different roles was a very good idea,' says David Lee. 'So now when somebody gets out of line we put on our hats and we rewind and get back into the right roles.'

As David speaks, Charlie slams a table tennis ball past Sammy. Both players occupy pivotal roles in the company and are responsible for enormous budgets and hundreds of employees but they seem entirely relaxed. David says his family has achieved this comfort level by studying the ways in which families can implode.

'A family is so difficult because you have no choice,' he says. 'In a job you can always quit but in a family, it's blood. You are born into this. And when you have kids you can't choose what kind of personality they have.'

Sandi and I.M. Pei have not developed the kind of formal structure that is used by the Lee family. Difficulties have tended to occur when the line between their father-son and architect-to-architect relationships has become blurred.

'I came to Hong Kong recently to present a design and before I left I showed it to my father,' says Sandi. 'He failed to say anything encouraging because it was probably not what he would have done and I think that's a bit frustrating; you want to get the support of your father [for your work], who you admire, and yet he is very reluctant to do that. I suppose I wish he would be more like a father in that regard.'

Sandi says he doubts that his father has had to learn much from the people around him. He has tried to take a different approach.

'The unique circumstance of my upbringing has made me more sensitive to the needs of my colleagues and staff,' says Sandi. 'Not only does it require greater leadership from me but it also entails greater recognition of others.'

The lack of clarity between professional and family roles has sometimes made it harder for Sandi to oppose his father whenever they have had creative differences.

'I think perhaps it is a little bit of a Chinese aspect of doing business,' he says. 'Being a son you have to be very respectful and challenging him too much is perhaps disrespectful.

'Anna is open and affectionate and I think that has allowed my father to come out of his professional shell and start nurturing in a different way,' he says.

When Sandi gave his father an iPod, it was Anna who programmed it with a library of classical music. 'She has changed him and that has enabled me as a son to become closer to my father. He is also more emotionally available, more aware of his limitations. He doesn't deny his diminished capacities; rather he accepts assistance and deference with grace and gratitude.'

In her book Asian Americans - Personality Patterns, Identity and Mental Health, Laura Uba observes that in Asian families, 'The old have higher status than the young; males have a superior position to females.' Uba says this hierarchy derives from cosmology, which requires a balance between yin (feminine, negative, inferior and weak) and yang (masculine, positive, superior and strong). In the past, girls were regarded as 'water being thrown out of the house' because they could not continue the family name. When women had a dominant role, the relationship between yin and yang was upset and disharmony was expected to follow. Uba concluded that, 'Traditional and rigid family roles may promote stability and security but they may also perpetuate emotional distance between father and children.'

One can sense that this distance has existed in the relationship between Sandi and I.M. Pei. It seems less of a factor between Lee Man-tat and his children, although tradition still plays a role. Elizabeth Mok (nee Lee) refused shares in Lee Kum Kee when her father offered them and since then it has been decided that ownership can only pass through bloodlines, with in-laws excluded from possessing shares. When it comes to organising their objectives the Lees embrace tradition.

'In Chinese philosophy, first we ask how can we improve ourselves,' says David Lee. 'Then we ask how can we contribute to and improve the family. And after the family we ask what we can do for the community.'

Man-tat was sceptical when his sons began insisting that the family spend so much time on self-improvement and mutual understanding but he was won over and endorsed the creation of a board position for a chairman of family development, currently held by Charlie, who finds consultants and coaches to join the family gatherings and conduct seminars, games and role-playing exercises. Uncles and nephews surf together, brothers play golf and for the family-oriented parts of the gathering, wives are asked to join in.

But even with all this focus on creating a harmonious family, being a father is not easy.

'The hardest part is acceptance,' says David Lee, who has two sons, 'to hold back and allow them to make their own choices. For example, my sons should only join the business if that's what they truly want to do. Unfortunately, I think we may have overwhelmed the fifth generation with choices but I think in time they will understand what we were trying to do.'

Stanley Szeto is among a new generation of Asian fathers who are taking a less traditional view of their role, although he is still part of a dynasty. His company, Lever Style, was founded by his grandfather 53 years ago. Szeto took over as chief executive from his father in 2001, when he was 27. Since then, he has tripled the size of the company and it now makes more than 10 million garments a year for an impressive list of fashion brands that includes Calvin Klein, Hugo Boss and Paul Smith. He is the father of four-year-old twins and has already begun to teach them humility, a value he holds in higher regard than any other.

'My dad grew up in Hong Kong during the second world war,' says Szeto, at his home on Stubbs Road. 'The family was not well off, he had to walk his brothers and sisters to school and use limited money to buy food. He taught us not to take anything for granted. Anything may happen, so we live frugally and flexibly. We do not live for material wealth but for relationships and other values that transcend money.'

Szeto describes his father as 'very traditional' with a focus on achievement.

'He drove us quite hard and I found that difficult when I was young but I have learned to appreciate what he did,' says Szeto, as he tends to his sleepy boys. 'My father taught and instructed. It wasn't very friendly, we didn't play together like I play with my sons.

'For the next generation you need a different style,' he says. 'It's not about being an instructor any more, it's more like being a friend or a coach. It's a closer relationship.'

The Pei and Lee families seem to have adapted traditional Asian values so they can be applied with a softer touch. In part, their motivation may be to avoid past mistakes.

'I admire my father but I think he probably does have some regrets about the way he raised us,' says Sandi Pei. 'I think he sees an opportunity to be much more affectionate towards his grandchildren; he really wants to reach out to them. My daughter sees his [professional] success and she is proud of him but I think he wants her to see him as her grandfather.'

Which illustrates one of the beneficial aspects of father-child relationships in dynasties - and families of all kinds. When the son or daughter has children of their own it allows the father, as grandfather, to have a second chance at parenting, an opportunity to do things better than before. And he can also have a role as a storyteller.

'My dad was able to tell me stories about hardship when I was a child,' says Szeto. 'Our kids won't have that. I had it because when I was young the business was struggling but to instil that in my boys I won't have many first-hand stories. I will ask my dad to share those stories with my kids, so they can understand how lucky they are.'

And that's part of the process of making sure the future is better than the past. Whether by the formal routines of the Lees, the intellectual soul searching of the Peis or the spontaneous love of the Szetos, three important Chinese dynasties are devoted to making sure the next generation is as strong as it can be.

'My greatest joy has been to see myself in my boys and to have an opportunity to mould two souls to see what they can be in the future,' says Szeto. 'Right now, they are a blank sheet and this is the greatest project you can have. Business is just one aspect of life; family is eternal.'

Styling: Kent & Curwen