Feelings aren’t everything. Empathy might be making the world a worse place, not a better one. Kindness can, in some senses, be a weakness. As popular arguments go, these are right up there with “strangle more kittens” and “death to rainbows”. If asked to list everything that’s wrong with modern Britain, few would choose a surfeit of goodwill and understanding.

Or certainly not in the week that Ukip donor Arron Banks complained he was “sick to death” of hearing about the Hillsborough disaster and of people “milking” the tragedy, while angrily defending the Ukip leader, Paul Nuttall, against charges of doing something not dissimilar. (Nuttall has blamed a press officer’s error for statements on his website wrongly suggesting that he lost “close personal friends” in the tragedy, for which he has apologised).

So when I started reading the American psychologist Paul Bloom’s new book, Against Empathy: The Case for Rational Compassion, it was mainly in the hope of picking holes. But instead it picked something of a hole in me.

His basic argument is that empathy – defined not just as warm, fuzzy feelings but the ability to feel someone else’s pain, to suffer when they suffer even if you are not personally afflicted – simply isn’t what it’s cracked up to be. Far from making us better or kinder people it actually clouds moral judgement, encourages bias, enfeebles parents (how do you make kids do their homework, or get painful vaccinations, if you can’t stand seeing them suffer?) and can get in the way of professionals doing their job.

The book isn’t remotely arguing in favour of unkindness, and Bloom is keener on what he calls “social intelligence”, or the attempt to understand why other people feel as they do even when the feeling is completely alien to you. (For example, to avoid insulting people who lost loved ones at Hillsborough, you don’t have to feel their pain; you just need the social skills to grasp the crassness of suggesting that other people’s grief is boring you).

But his central message is less heart, more head; less gooey emoting, more objectivity and distance, allowing for a fairer assessment of who really deserves our compassion. Don’t just feel. Use your brain, and think.

“Down with empathy” is, however, a counterintuitive thing to say in a political climate which has shown millions of Britons and Americans that they clearly didn’t know their fellow citizens as well as they thought. Surely wanting to walk a mile in someone’s shoes is good, in the circumstances? Wasn’t the whole problem that the haves and have-nots, liberal cities and resentful suburbs, angry dispossessed men and newly assertive women, had stopped trying to feel each other’s pain?

But in a way, that’s Bloom’s point. We like to think empathy bridges these gaps, but actually humans empathise most easily with people from backgrounds similar to themselves, and are surprisingly good at overlooking the pain of people they don’t like.

When Diane Abbott wrote this week about the racist abuse she has received throughout her political career, I was struck by how many responses on social media boiled down to “Yeah, but she said that thing that annoyed me once, so …” People simply couldn’t see past their personal irritation with her or her views. A society overly reliant on empathy can mean gushing warmth for people whose faces fit, and stony indifference to the rest, even when logically they deserve better. That’s not breaking down barriers, but reinforcing them.

The second problem is that it’s easier to empathise with specific individuals than vast faceless groups. Sometimes that’s simply to the detriment of the greater good, as when one winsomely needy child catches the public imagination and is showered with kindly donations at the expense of more deserving cases. But it also means empathy can fizzle out surprisingly quickly, because it doesn’t scale up.

A picture of a tiny lifeless body washed up on a Turkish beach tugs at all our consciences, because anyone looking at it feels their heart go out to the boy’s grieving parents. But the emotional response to that highly charged photograph of Alan Kurdi didn’t ultimately change attitudes to thousands of other families crossing the Mediterranean, whose lives still seemed so alien. Feelings are fickle, a surprisingly puny substitute for thinking.

This is awkward for everyone, myself included, who saw Brexit as a cautionary lesson in the importance of being able to play on people’s emotions; who thought liberals just needed more compelling stories, or smarter ways of doing the touchy-feely stuff, or greater closeness to the experiences of people they’re supposed to represent.

For the new politics of empathy sells itself less on what politicians know or can do, than on how much they’re like the voter. The idea that politicians can and should respond to evidence rather than merely their own life experiences – that even MPs who have never personally struggled to pay the rent could rationally choose to help the low paid, for example – is vanishing. As Nuttall himself says, voters want to see “real people who they can empathise with representing them”, so they naturally look for shared experiences and feelings.

And that’s why Nuttall’s insistence that he was at Hillsborough that day, that he knew (if not that well) some of those who died, has become so intrinsic to his political identity. For both sides in the Stoke byelection, the row over his Hillsborough experiences has become a litmus test of authenticity, of whether he is who he says he is – a working-class northern lad, shaped by similar experiences to the people he wants to represent.

But what does it really prove? Nuttall says he still bears the scars of that day, that he suffered along with everyone else who was there, yet seems to have had little historic involvement with the families’ campaign for justice. At the time of writing he couldn’t even bring himself to criticise Banks’s offensive remarks. Empathy without the skills to act on it, or the ability to stand back and judge people objectively, turns out not to be worth very much.

So what of Bloom’s less exciting but steadier alternative, the exercise of reasoned compassion?

The Hillsborough judicial process is painfully slow, dry, and impersonal. Even when their painstaking campaign for a new inquest was eventually granted – thanks in no small part to the dogged efforts of Labour’s Andy Burnham – the families had to endure two tortuous years of evidence and the repetition in some cases of what they regard as heinous slurs.

But it was the application of open mind to evidence that delivered justice in the end, and that’s a reminder of why reason is precious.

It’s so easy to be swept along on a tide of feeling, to decide that this is an age of emotion and everyone must simply adapt, but in the process something important is being lost. Love doesn’t always trump hate, no matter what the placards say, but reasoned argument can. Don’t just feel. Use your brain, and think.