New Scientist - USA (2019-11-30)

14 | New Scientist | 30 November 2019

MARRIED heterosexual men feel

most comfortable when they earn

50 per cent more than their wives,

according to a study of data from

the US.

Over the past few decades,

more and more women have

started to out-earn men. Joanna

Syrda at the University of Bath

in the UK wanted to investigate

the psychological effects of this

change. She analysed data from

a US survey of more than 6000

married heterosexual couples that

included questions about income

and emotional well-being.

So far she has focused on the

effects in men. She found they

tended to be unhappier when

their wives earned more than

them, becoming gradually more

so as their wives’ earnings grew

relative to their own. This was

unrelated to total household

income, the amount of housework

the men did, or the hours their

wives worked.

Men who were the sole

breadwinners were also relatively

unhappy, perhaps due to the

stress of being the family’s only

financial source. But they weren’t

as unhappy as men who earned

less than their wives.

The men who were happiest

were those who earned 60 per cent

of their households’ total income

and whose wives earned 40 per

cent. This is probably the point at

which wives earn enough money

to minimise financial strain on

their families without challenging

the traditional stereotype of the

male breadwinner, says Syrda

(Personality and Social Psychology

Bulletin, doi.org/ggb5mk).

“The male breadwinner

identity  – the idea that a man

must take care of his family – has

been incredibly durable despite

many other changes to gender

norms,” says Syrda. “These

findings show that it can actually

be harmful to men’s mental health

because they feel emasculated if

their wives earn more than them.”

Nicholas Haslam at the

University of Melbourne in

Australia agrees. “Even if men

think they’re beyond all of this

sexist stuff, very often they’re

not,” he says. “The fact that

men are happiest when women

earn two-thirds what they do

shows we have a long way to

go to reach equality.”

However, not all men feel

the same way, says Syrda.

Her analysis found that men

whose wives earned more than

them when they got married

didn’t experience the same

discomfort. This is probably

because men who choose to pair

up with high-earning women feel

less threatened by female success

to begin with, she says.

The way happiness was

measured in the study – by asking

respondents how often they had

negative thoughts in the past

30 days – was fairly crude, says

Haslam. However, it still provided

a useful snapshot of general well-

being, he says.

Syrda now wants to compare

how women are affected by male

partners’ earnings. She also plans

to see how income differences

affect same-sex couples. ❚

Psychology

Alice Klein

News Canine calculator
Work out your dog’s age in human years
newscientist.com/dog-age

Dogs hit the equivalent

of human middle age

after only a few years

Animals

Formula for

calculating your

dog’s real age

YOU may need to rethink your

dog’s age. Conventional wisdom

says that one human year is the

equivalent of seven dog years,

but a new analysis suggests we

have been getting this all wrong.

The seven dog years to every

human year rule comes simply from

crudely dividing human lifespan,

around 80 years, by dog lifespan,

typically 12 years. Trey Ideker

at the University of California,

San Diego, and his colleagues

found that the rule is a little off.

The team performed a genetic

analysis of dogs and humans

to identify how they age over

time. The researchers discovered

that, compared with us, dogs age

faster at first, blazing into the

equivalent of human middle age

after only a few years.

But this ageing quickly tapers

off, with the next 10 years only

accruing two human decades’

worth of changes. The team put

this together into a single formula:

human age = 16 ln(dog age) + 31

(see the top of the page for a link

to our online dog age calculator).

It is a significant revision to

our understanding of how to map

dogs against their human owners

in terms of age, says Ideker.

The team studied 104 Labradors,

ranging from very young puppies

to 16-year-old dogs. The

researchers then compared the

dogs’ methylomes – a set of

chemical changes to genes that

fluctuates throughout life – to

those of humans over a lifetime.

By matching these methylomes, the

researchers could convert between

the physiological age of dogs and

humans (bioRxiv, doi.org/dftv).

In both, these age-related changes

largely involved developmental

genes found in all vertebrates that

are important from their time in the

uterus through their childhood.

Matt Kaeberlein at the University

of Washington in Seattle says it

would be interesting to find out

what happens to the age clock

in dog breeds with very different

lifespans, such as Great Danes

and chihuahuas. ❚

Jake Buehler

Heterosexual husbands happiest

when they out-earn their wives

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“ The male breadwinner

identity has been durable

despite many other

changes to gender norms”