Happiness, a Mystery by Sophie Hannah review – solving the most profound puzzle

<span>Photograph: David Hartley/Rex</span>
Photograph: David Hartley/Rex

What if we brought a detective’s logic to bear on the search for happiness? In this book, the bestselling crime writer Sophie Hannah sifts the evidence in order to solve the greatest case of all. Chosen by the Agatha Christie estate to continue the Hercule Poirot canon, Hannah teaches at Cambridge, writes poetry and is a connoisseur of self-help literature. Yet, prodigious as her skills are, the task remains a daunting one. As she writes: “What are the chances that a crime writer with frizzy hair and unhoovered carpets could solve such a profound mystery so quickly and easily?”

An early chapter offers a zippy precis of the “big-boy theories” of happiness, from Platonic self-actualisation to Stoic acceptance, Benthamite utilitarianism and Kant’s pursuit of virtue. This is “the case file so far”. The “66 attempts” of her subtitle – clues scattered like breadcrumbs through the book – amount to a mood-improvement system, a schedule of creative prompts that force one into engaging with life, rather than theorising about it. They include: “Promise Something”, “Admit Something”, “Invent Something”, “Write to Someone”, “Cancel Something”. And of course, as in every good crime tale, there’s a twist, which is also an epiphany.

Her tone is very British: sceptical, jokey – happy to reveal the bag of crumbs tucked in her bra, out of reach of the dog

Before we get there, Hannah’s focus is, perhaps surprisingly, on the lessons to be learned from popular life coaches, including Kate Swoboda, Gretchen Rubin, Kara Loewentheil, and particularly Brooke Castillo. The latter’s principal argument is that feelings are decided by thoughts, which can be consciously chosen, and much of Hannah’s book is given over to grappling with this idea (derived from the Stoics and spiritual teacher Eckhart Tolle, among others). Her attraction to self-assured, aspirational Americans is often at odds with her very British tone: jokey, sceptical – happy to reveal the paper bag of pastry crumbs tucked in her bra, out of reach of the dog.

Hannah finally decides that all the attention she has paid to positivity gurus has been procrastination: she has put them on a pedestal because “they feel so far away from my real life, and I have an innate bias that keeps whispering ‘the further away from your reality, the better’.” But there is a related concern. Is happiness – such a fugitive state of mind – amenable to detection or logic at all? Charlotte Brontë skewered the notion in her novel Villette: “Happiness is not a potato, to be planted in mould, and tilled with manure.” These days, we prefer our happiness gurus to have arrived at their commandments via crappy experiences. Revelations of suffering – akin to religious purification – are prerequisite for telling others how to live. But Hannah’s story seems a little different, her motivation more opaque.

She glancingly refers to not wanting her friends to know about her inner life “if there is any sadness or anger in it”. And she mentions, without going into detail, a man who behaved in ways that oppressed her for years. But in her first therapy session, Hannah prefers to say: “I think I might be too happy.” Her main worry seems to be having too much to do: “The other day, I was properly, genuinely pleased when I worked out a way of washing my face and brushing my teeth at the same time. I saved between seven and ten seconds by … washing my face around my toothbrush.” The only bully in her life now is her workload: “Maybe I don’t feel comfortable unless there’s an oppressive tyrant in my life, and so, when I ran out of human contenders for the position, I made my work ‘It’.”

This is far from a dark book, however. It’s a pleasure to be in Hannah’s company, and to address the subject of happiness without having to crawl by proxy through a dark night of the soul. The author is at her most charming when most contrary and questioning. A dog-owning acquaintance is, Hannah believes, trying to kill her pet by deliberately leaving her front door ajar. Castillo would argue there are no inherently bad actors – to love everyone unconditionally, with great spiritual compassion, is the way to safeguard one’s happiness. Hannah’s instincts are gratifyingly less enlightened: she simply doesn’t want a dog-murderer for a friend. Can changing our judgments transform negative feelings into positive, she wonders. Are thoughts even optional?

Related: Why I'm addicted to self-help books | Sophie Hannah

The author does her best to fulfil her “mystery” pitch for the book, which her publishers loved, though her approach sometimes seems more like neurotic doodling than lessons forged in fire. Towards the end, she reflects: “I’m a traditional crime writer. I believe mysteries need to have proper solutions ... what if the mystery of happiness can’t be solved decisively?”

Happiness, a Mystery is optimistic – the belief that happiness is within reach forms a key part of its conclusion. This news is delivered gleefully via the twist, which shouldn’t be revealed here, but emphasises process, the journey rather than the destination. This is the most satisfying section of the book – crime writers of calibre always stick the landing – even if the sense lingers that one has been offered a display of mischievous brain gymnastics rather than a tangible solution. Hannah’s peculiar, exasperating, funny and immensely readable shaggy dog story is worth being gathered into the drawing room for, in any case.

• Happiness, a Mystery & 66 Attempts to Solve It is published by Wellcome (£12.99). To order a copy go to guardianbookshop.com. Delivery charges may apply.