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Wellcome Collection | Sexology Season

Sex by numbers

It’s no secret that Brits are pretty shy about sharing their bedroom behaviours. But for most of us, this only makes the truth more tantalising. In 1990, Natsal began – Britain’s National Surveys of Sexual Attitudes and Lifestyles.

They are the largest scientific studies of sex in the world to date, lifting the lid on the sex lives of over 45,000 people. Professor David Spiegelhalter has explored this data and more in his book, Sex by Numbers, that accompanies the Wellcome Collection's Sexology Season. Scroll down for a look through the window into the world of sex...

Read more about Natsal and Sex by Numbers

How many times has the average person had sex in the past 4 weeks?

This graph shows the average number of times people have had sex (with someone of the opposite sex) in the past 4 weeks, by survey year. It’s measured by the median, which is the value halfway along the distribution of the answers given by everyone who is sexually active, which means they have had at least one same opposite-sex partner in the last year.

These results are from Natsal-1 (1990–91), Natsal-2 (1999–2001) and Natsal-3 (2010–12) and are for sexually active people aged 16–44, as all the surveys cover this age range.

Frequency of sex in past 4 weeks - all ages (16 to 44)
Survey yearMenWomen
199055
200044
201033
Frequency of sex in past 4 weeks - ages 16 to 24
Survey yearMenWomen
199035
200035
201034
Frequency of sex in past 4 weeks - ages 25 to 34
Survey yearMenWomen
199065
200055
201044
Frequency of sex in past 4 weeks - ages 35 to 44
Survey yearMenWomen
199055
200044
201033

So it seems people are having less sex. But why? Experts suggest that our over-connection with the digital world may be leading to less connection in the bedroom.

Let’s hope this rate of decline doesn’t continue, as otherwise by 2040 the average person may not be having any sex at all.

How many sexual partners has the average person had in their lifetime?

This graph shows the average number of opposite-sex partners people have had in their lifetime so far. It’s measured by the median, which is the value halfway along the distribution of everyone’s answers. These results are from Natsal-3 (2010–12) only and are for people aged 16–74.

Age groupMenWomen
16-2433
25-3465
35-4485
45-5484
55-6453
65-7442

Surprisingly, it seems the older women have had fewer partners. Intriguing when you think they’ve had more time to add to their collection. It shows that behaviour has changed between women born in the 1930s and those born in the 1970s.

These averages mask the great variation in people’s experiences, with the most common response being precisely one, in stark contrast to the few who reported more than 500 partners.

What proportion of people have ever had a same-sex experience?

This graph shows the percentage of the population who have ever had a sexual experience with someone of the same sex as them.

These results are from Natsal-1 (1990–91), Natsal-2 (1999–2001) and Natsal-3 (2010–12) and are for people aged 16–44.

Any experience
Survey yearMenWomen
199064
2000810
2010716
Genital contact
Survey yearMenWomen
199042
200055
201058

When it comes to same-sex experiences, the situation is not the same for both sexes. While there’s been little change for the men, women’s behaviour has seen a leap over relatively little time.

And kissing is just half the story: around 50% of these women reported genital contact too. While activity has clearly increased, some evidence suggests women are also more open to sharing their stories.

What types of sex have people in Britain had in the past year?

This graph shows the percentage of the whole population who said they had had different types of sex in the past year: with people of the opposite sex or the same sex as them.

These results are from Natsal-3 (2010–12) only and are for all people aged 16–74.

Participants were given definitions of different types of sex, developed after interviews with members of the public before the first Natsal survey, exploring the best way to describe different types of sex. These definitions were designed to correspond with the most commonly used lay terms, and also enable us to collect data to help understand the transmission of HIV and other STIs.

Opposite sex: vaginal
Age groupMenWomen
16-247475
25-348991
35-449189
45-548581
55-647559
65-745737
Opposite sex: oral
Age groupMenWomen
16-247170
25-348080
35-448075
45-547163
55-645235
65-743019
Opposite sex: anal
Age groupMenWomen
16-241917
25-341816
35-441513
45-54148
55-6484
65-7434
Opposite sex: other
Age groupMenWomen
16-247173
25-347677
35-447373
45-546662
55-645641
65-743728
Same sex: vaginal
Age groupMenWomen
16-2400
25-3400
35-4400
45-5400
55-6400
65-7400
Same sex: oral
Age groupMenWomen
16-2422
25-3432
35-4422
45-5431
55-6421
65-7410
Same sex: anal
Age groupMenWomen
16-2420
25-3420
35-4420
45-5420
55-6410
65-7400
Same sex: other
Age groupMenWomen
16-2423
25-3422
35-4423
45-5422
55-6410
65-7400

People have sex at all ages, although older people don’t have so much, or so much variety. Many no longer have a partner, and ill health doesn’t help. And some decline is due to the length of time people have been together, rather than just age itself.

Nevertheless, over the last 20 years people have introduced more variety into their sexual repertoire, with increases in both oral and anal sex. Anal sex remains a rarity, although twice as many have tried it than had 20 years ago.

What proportion of people have masturbated in the past 4 weeks?

This graph shows the percentage of people who masturbated in the past 4 weeks, by sex and age group.

These results are from Natsal-3 (2010–12) only and are for people aged 16–74.

All
Age groupMenWomen
16-248337
25-347844
35-447340
45-546538
55-645319
65-743310
Living with partner
Age groupMenWomen
16-247434
25-347640
35-447237
45-546435
55-645319
65-743311
In a steady relationship but not living with partner
Age groupMenWomen
16-248442
25-348254
35-447950
45-545850
55-646024
65-743913
Not in a steady relationship
Age groupMenWomen
16-248535
25-348251
35-447748
45-547042
55-645320
65-74329

Masturbation – science shows it to be a safe and positive part of our sexual health, now that blindness, insanity, clammy hands and pimples have finally been ruled out as side-effects!

For men this may come as a relief, for twice as many men as women are masturbating. Being in a relationship doesn’t seem to change things either, since rates are only slightly higher for those with no current partner.

How has the average age at first sex changed over time?

This graph shows the median age at first heterosexual intercourse, by participants’ year of birth, showing how this has changed over the decades.

These results are from Natsal-3 (2010–12) and are for people aged 16–74.

Year of birth (1935 - 1996)MenWomen
35-391920
40-491819
50-591718
60-691717
70-791717
80-891717
90-961616

The average age when people first have sex has definitely fallen in the last 60 years, 16 being the magic number for both men and women born in the 1990s.

The gender gap has also closed from previous years. Around 1 in 7 men born in the early 1950s reported having sex before 16, and around 1 in 10 women; but around 1 in 3 of the 1990s generation lost their virginity before they hit the legal age of consent.

Interestingly, economics has an influence too, with more young people in more deprived areas having sex before 16.

What proportion of people have used sexual health services?

This graph shows the percentage of people who have visited a sexual health clinic or had an HIV test in the past 5 years.

These results are from Natsal-1 (1990–91), Natsal-2 (1999–2001) and Natsal-3 (2010–12) and are for people aged 16–44. These questions were only asked of people who had ever had sex.

Clinics
Survey yearMenWomen
199043
200087
20102021
HIV testing
Survey yearMenWomen
1990711
200099
20101728

Since the first Natsal survey in 1990–91, many more people have been using sexual health clinics and having HIV tests, with 1 in 5 doing so in 2010–12.

Generally, high-risk behaviours have not increased, so this change is probably due to improved services and willingness to be tested.

What proportion of people have experienced sex against their will?

These bars show the proportion of men and women who reported that someone had made them have sex against their will.

These results are from Natsal-3 (2010–12) only and are for people aged 16–74.

MenWomen
Total1/711/10

Of those who report having sex against their will, who was responsible?

These bars show who was responsible (the most recent occurrence, if it had happened more than once).

Intimate partner (former / current)
Family or friend
Other acquaintance
Stranger
Other
Intimate partner (former / current)
Family or friend
Other acquaintance
Stranger
Other
Person responsibleMenWomen
Intimate partner (former/current)2341
Family or friend3020
Other acquaintance3021
Stranger1515
Other23

1 in 10 women have experienced sex against their will, while 1 in 71 men have.

In the majority of cases, the person responsible was someone they knew. The results also reveal that fewer than half told someone, and even fewer reported it to the police, even when a stranger was responsible.

How have our attitudes towards sex changed?

Participants in the Natsal studies were read a series of statements about different types of relationships and were asked to give their views about each one: always wrong, mostly wrong, sometimes wrong, rarely wrong, or not wrong at all.

The graph shows the percentage of people who answered ‘always wrong’ to each statement.

These results are from Natsal-1 (1990–91), Natsal-2 (1999–2001) and Natsal-3 (2010–12) and are for people aged 16–44.

Attitude 1: Sex outside of marriage is always wrong
Survey yearMenWomen
19904553
20005160
20106370
Attitude 2: One night stands are always wrong
Survey yearMenWomen
19903156
20001932
20102230
Attitude 3: Same sex (male) relationships are always wrong
Survey yearMenWomen
19905742
20003920
20102714
Attitude 4: Same sex (female) relationships are always wrong
Survey yearMenWomen
19904742
20002619
20101814

Our attitudes towards sex have certainly changed. While both sexes have become more accepting of same-sex partnerships, they’ve become less accepting of a married person having sex with someone other than their spouse. Many men, and even more women, stand against one-night stands, but the gap is closing.

When it comes to our sex lives we all like to keep a few secrets – which makes the jobs of sexologists pretty difficult.

Luckily, Professor David Spiegelhalter is here to unravel the web of exaggerations, misdirections and downright lies that surround sex in modern society. Drawing on the Natsal survey, he answers crucial questions such as: what are we all doing? How often? How has it changed?

Accompanying The Institute of Sexology - a major Wellcome Collection exhibition - Sex by Numbers is an informed and entertaining look at the most enduring of human obsessions.

Explore the Season Buy the Book

Britain’s National Surveys of Sexual Attitudes and Lifestyles (Natsal) are among the largest and most detailed scientific studies of sex in the world to date.

Three Natsal surveys have been carried out so far: in 1990–91, 1999–2001, and 2010–12. Rather than asking for volunteers, they selected participants using random sampling methods to give a representative picture of the population. The questions about sexual behaviour, experiences and attitudes use a combination of face-to-face and self-completion interviewing. More than 45,000 people have been interviewed.

The surveys are carried out by researchers at University College London, the London School of Hygiene and Tropical Medicine, and NatCen Social Research. The latest survey was funded through grants from the Wellcome Trust and the Medical Research Council.

For more information about Natsal, visit natsal.ac.uk.


Sex by Numbers: The Statistics of Sexual Behaviour by Professor David Spiegelhalter draws on the Natsal data and answers crucial questions such as - What are we all doing? How often? How has it changed? Available from all good bookshops and online. Find out more by scrolling to the end of this site.