Stealing Water, by Tim Ecott. If You Don't Know Me, by Now, by Sathnam Sanghera

A novelist, Simenon said, is a man whose mother didn't love him. Judging from these books, memoirists are the opposite sons of fiercely loving and beloved mothers, who stood between them and the world. It's fathers who are the trouble here.

Tim Ecott's was a soldier, the son of middle-class parents who gave him a top-notch education but little else. He was moody, anti-social, relying on prejudices (e.g. about Jews) to release his anger. So far, a standard English emotional cripple. But Stuart Ecott was also more practical trouble to his family hopeless about money. Tim doesn't ask why; he doesn't ask anything much. But it's clear Stuart was a naive fantasist, cut off in lonely independence from the age of four, with never more than a four-year-old's understanding of other people.

It was left to Tim's mother wild Irish Pam to keep the family going. This she did, by running a junk shop in Johannesburg, where the Ecotts emigrated after Stuart left the army. This is the story of their rackety, sometimes illegal life, so poor that they were reduced at one stage to stealing water.

Stealing Water has its moments, whenever Pam and the South African landscape appear. But Tim is too like his father. Instead of real engagement, he gives us sketches of the unsavoury characters who hang around the shop, and tries to do their voices, which is always a mistake. His rare reflections are kinder than Stuart's, but just as naive ("It was a shock to see my aunt with her young boyfriend, sometimes ignoring her responsibilities as a parent"). He dots his text with references to old movies "Grand Hotel (Greta Garbo, Lionel Barrymore, 1932)" in a brave attempt to amuse, which only reminds us of his anxious and obsessive adolescence. And underneath the bravery runs a constant thread of violence, centred on his father. I think Tim was afraid of him. If he'd written about that, it might have made a good book.

There are secrets in Stealing Water, but they have no consequences., by contrast, If You Don't Know Me, by Now is about real secrets, in a real quest for understanding. It's tragic, funny and disturbing. It will challenge you, and may even change you. In other words, it's literature.

Sathnam Sanghera has not just one but three stories to tell, cunningly woven together. The first is his own: the youngest son of poor, illiterate, non-English-speaking Punjabi immigrants, who moves from Wolverhampton Grammar to Cambridge and finally London, where he lives the gilded life of a financial journalist with his own flat, private health insurance, and a string of English girlfriends. This last unleashes the dilemma that gave birth to the book: how to tell his mother. On page 1 he decides to write her a letter; on page 310 he finally delivers it. In between, he makes fun of his indecision, and vividly describes her combination of limitless love and a hair-raisingly limited world view, ruled, by custom and superstition unchanged for hundreds of years, and above all, by the requirement that her children marry not just Sikhs, but Jat Sikhs of a particular height and shade.

He is funny about this too: the absurd failures of his meetings with Sikh girls; and his mother's sorrow over honour killings genuine, but like "that of an American president apologizing for civilian casualties in a necessary war".

In between come other stories. One is the story of the book, its research and writing, which Sanghera uses to reveal his discovery of the last story: that of his parents' marriage, and the secret of his father's and eldest sister's illness. This secret is the tragic heart of the memoir: I won't give it away; and I won't tell you how Sathnam's mother responds when he finally gives her his letter. I hope you find out for yourself.

I can tell you that his reflections on keeping secrets in families are unorthodox:, by keeping his father's illness a secret from her children, he writes, his mother saved him, and saved them. His revelations of Punjabi immigrant life are even more un-PC. Some are shocking the alcohol abuse and domestic violence, the narrowness and superstition, the disabling ignorance of the British world. These make Sanghera despair, and rail against "the multiculturalists out there" who argue that immigrants shouldn't be forced to learn English.

I am one of them, and his account of the results for his parents changed my mind. But he tells us that Indian families cope better with illness like his father's, because they don't medicalise it. And look at him and his brother and sisters, obediently married to Sikhs, not Cambridge graduates like him, but educated and English-speaking. If You Don't Know Me, by Now will make you think, but it won't make you decide. It is, as I say, literature.

Carole Angier's biography 'Primo Levi: the double bond' is published, by Penguin