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0:00:09 > 0:00:11- It can take us by surprise.
0:00:16 > 0:00:18- Most of us hope to find it.
0:00:23 > 0:00:26- It can make us happy and sad...
0:00:27 > 0:00:29- ..crazy and content.
0:00:31 > 0:00:34- And we hope it lasts for ever.
0:00:36 > 0:00:40- Love affects the way we think - and the way we behave.
0:00:41 > 0:00:44- What is love - and what does it do to the body?
0:00:45 > 0:00:47- Why does it exist - in the first place?
0:00:56 > 0:01:01- In this Corff Cymru special, - we cast a scientific eye over love.
0:01:01 > 0:01:05- I'm Dr Anwen Jones, - a Physiology And Health lecturer...
0:01:05 > 0:01:08- ..at Cardiff - Metropolitan University.
0:01:09 > 0:01:14- I'm Dr Katie Hemer, a Bioarchaeology - lecturer at Sheffield University.
0:01:14 > 0:01:19- We'll look at scientific research - into the physiology of love...
0:01:19 > 0:01:24- ..and we'll meet leading experts to - discover how this unique feeling...
0:01:25 > 0:01:29- ..has such a huge impact - on our bodies and on our lives.
0:01:30 > 0:01:33- We'll ask what happens - when we fall in love...
0:01:34 > 0:01:37- ..what influences - our search for love...
0:01:37 > 0:01:41- ..and how uniquely human - love actually is.
0:01:49 > 0:01:51- Falling in love changes us.
0:01:55 > 0:01:58- It affects the way we think - and the way we behave.
0:02:01 > 0:02:05- Something happens in the brain - when we fall in love...
0:02:05 > 0:02:07- ..to trigger these huge changes.
0:02:11 > 0:02:15- What effect does falling in love - have on the brain?
0:02:18 > 0:02:22- Does love's magic last for ever - or is it just temporary?
0:02:22 > 0:02:26- Does love's impact on the brain - change over time?
0:02:32 > 0:02:35- To look at the effect - love has on the brain...
0:02:35 > 0:02:40- ..I'm meeting Ceri Ellis at Bangor - University's Psychology Department.
0:02:41 > 0:02:46- Couples who've been together for at - least four years were recruited...
0:02:46 > 0:02:50- ..to participate - in a special research project.
0:02:50 > 0:02:54- The couples are asked - to write a list of Love Words...
0:02:54 > 0:02:58- ..which have meaning for them - as a couple.
0:02:58 > 0:03:02- The couples are separated - and enter two different rooms.
0:03:02 > 0:03:05- They wear EEG caps - which monitor brain activity.
0:03:06 > 0:03:11- Love Words are mixed with standard - negative and positive words...
0:03:11 > 0:03:15- ..and they're displayed - on the screen, one at a time.
0:03:16 > 0:03:21- The person presses the space bar - every time they see a negative word.
0:03:21 > 0:03:25- They also read the positive words - and the love words.
0:03:26 > 0:03:30- Scientists can measure the brain's - reaction to specific words...
0:03:31 > 0:03:36- ..and compare the brain's reaction - to the different groups of words.
0:03:37 > 0:03:41- The individuals within each couple - are stimulated by love words.
0:03:42 > 0:03:46- They trigger a stronger reaction - than the positive words.
0:03:47 > 0:03:48- I can see a peak here.
0:03:49 > 0:03:53- Yes, and this shows an extremely - quick process in the brain.
0:03:54 > 0:03:57- The reaction peaks - at 600 milliseconds...
0:03:57 > 0:03:59- ..after they see the word.
0:04:01 > 0:04:03- We don't even notice this response?
0:04:04 > 0:04:05- No, we don't.
0:04:06 > 0:04:09- Both people - are unaware of their reaction.
0:04:09 > 0:04:12- It stems from - their shared experiences.
0:04:13 > 0:04:15- This demonstrates...
0:04:15 > 0:04:20- ..that these love words - trigger a strong emotional reaction.
0:04:23 > 0:04:28- The EEG cap also offers clues about - which part of the brain reacts.
0:04:28 > 0:04:33- This picture tells us which part - of the brain reacts to love words.
0:04:33 > 0:04:35- This red area...
0:04:35 > 0:04:39- ..is the part of the brain - which reacts to love words.
0:04:41 > 0:04:44- We can see which parts of the brain - are most active.
0:04:45 > 0:04:48- Are these the language and words - areas of the brain?
0:04:49 > 0:04:52- Yes, and when you see - language-related research...
0:04:53 > 0:04:57- ..this is the area of the brain - which is usually activated.
0:04:58 > 0:05:03- There's also evidence to suggest - this area also deals with emotion.
0:05:03 > 0:05:07- What effect does being in love - have on the brain?
0:05:07 > 0:05:11- The research shows us that - the processes of being in love...
0:05:12 > 0:05:17- ..and shared experiences can change - the way we deal with the world...
0:05:18 > 0:05:23- ..through forging strong emotional - links with what we do every day.
0:05:24 > 0:05:28- This research shows that love - has a direct impact on the brain.
0:05:28 > 0:05:34- It even shows that areas which deal - with language, memory and emotion...
0:05:34 > 0:05:36- ..play a part in this.
0:05:36 > 0:05:39- Which areas of the brain - are shaped by love...
0:05:40 > 0:05:43- ..and are those changes permanent?
0:05:44 > 0:05:50- Further research, using techniques - like MRI, is needed to answer that.
0:05:50 > 0:05:55- When you fall in love, chemicals - rush around your brain and body.
0:05:55 > 0:05:57- What chemicals are important?
0:05:58 > 0:06:02- When you're with your partner, - especially in the early days...
0:06:02 > 0:06:06- ..your heart races, - you blush and your hands sweat.
0:06:06 > 0:06:10- You can blame the chemical - noradrenaline for that!
0:06:10 > 0:06:15- Dopamine is the chemical in charge - of our pleasure-reward system.
0:06:15 > 0:06:20- Dopamine makes us feel happy and - is released when we see our partner.
0:06:21 > 0:06:24- When we spend time - with our partner...
0:06:24 > 0:06:27- ..the brain - releases the hormone oxytocin.
0:06:27 > 0:06:32- The same hormone is released between - mother and baby to form a bond.
0:06:32 > 0:06:36- Oxytocin - and vasopressin, another hormone...
0:06:36 > 0:06:39- ..are vital - to forming lasting bonds.
0:06:39 > 0:06:42- Endorphins also play a part - in long-term bonding.
0:06:43 > 0:06:47- Endorphins, the body's natural - painkilling chemicals...
0:06:47 > 0:06:50- ..are released - when we see our partner.
0:06:50 > 0:06:52- They make us feel happy and safe.
0:06:53 > 0:06:57- Several chemicals in the body - come into play when we fall in love.
0:06:58 > 0:07:03- They work together over time as the - bond between partners gets stronger.
0:07:15 > 0:07:17- Thank you.
0:07:17 > 0:07:22- Apparently, some foods and drinks - can stimulate romance.
0:07:22 > 0:07:25- They're called aphrodisiacs.
0:07:28 > 0:07:34- It's believed consuming aphrodisiacs - affects the body in such a way...
0:07:34 > 0:07:38- ..that they stimulate feelings - of love or romance.
0:07:45 > 0:07:50- Is there science behind aphrodisiacs - or are they old wives' tales?
0:07:52 > 0:07:58- Historically, aphrodisiacs appear - in many cultures across the world.
0:07:59 > 0:08:03- The shape can influence the - labelling of food as an aphrodisiac.
0:08:04 > 0:08:09- But it's thought other aphrodisiacs - have properties which boost libido.
0:08:10 > 0:08:15- To discover more about aphrodisiacs, - I'm in Canna Deli, Cardiff...
0:08:15 > 0:08:19- ..to meet Elin Williams, - who has some special food for me.
0:08:20 > 0:08:25- Oysters are well-known aphrodisiacs. - What's so special about them?
0:08:25 > 0:08:27- Oysters are rich in zinc...
0:08:28 > 0:08:33- ..which helps the body produce - testosterone and oestrogen.
0:08:33 > 0:08:37- Watermelon is packed with vitamins - which are vital to the body.
0:08:38 > 0:08:42- Vegetables like asparagus - are packed with vitamin E.
0:08:43 > 0:08:45- Bananas are rich in potassium.
0:08:46 > 0:08:51- Hormones like testosterone and - oestrogen play a big part in love.
0:08:51 > 0:08:56- Foods rich in vitamins and chemicals - which boost these hormones...
0:08:56 > 0:08:59- ..are likely to affect the body.
0:09:00 > 0:09:05- Foods which boost circulation are - also considered to be aphrodisiacs.
0:09:05 > 0:09:10- Chilli quickens the heart rate - and ginger boosts our circulation.
0:09:12 > 0:09:17- These things are linked to what - happens to us when we fall in love.
0:09:17 > 0:09:20- There's a lot of basil - in these dishes.
0:09:22 > 0:09:26- On the pizza, in the salad - and in the pesto.
0:09:26 > 0:09:30- In the olden days, - women rubbed basil on their chest...
0:09:31 > 0:09:35- ..because they believed - men were attracted to its aroma.
0:09:36 > 0:09:39- I can see chocolate over there.
0:09:40 > 0:09:44- Chocolate contains serotonin, - a chemical which affects the brain.
0:09:45 > 0:09:47- It makes you feel happy and relaxed.
0:09:47 > 0:09:51- Chocolate also contains - phenylethylamine...
0:09:51 > 0:09:56- ..a chemical compound produced - by the brain to make us feel alive.
0:09:56 > 0:09:59- Eating chocolate - may well make us feel happy.
0:10:01 > 0:10:06- Elin, do you believe there's - such a thing as aphrodisiac food...
0:10:06 > 0:10:08- ..or is it an old wives' tale?
0:10:08 > 0:10:13- The food you see here is nutritious - and generally good for the body...
0:10:13 > 0:10:19- ..and I think the chemicals in some - of them affect people's behaviour.
0:10:19 > 0:10:24- It depends on that person's mood - and who they're with.
0:10:26 > 0:10:31- Scientific evidence doesn't support - the theory that aphrodisiacs exist.
0:10:31 > 0:10:35- These foods' effect on our mood - may be all in the head.
0:10:35 > 0:10:39- Why then do so many cultures - believe in their existence?
0:10:39 > 0:10:41- They include chemicals...
0:10:41 > 0:10:45- ..which can potentially - affect the brain and body...
0:10:45 > 0:10:50- ..but do these foods contain enough - of them to affect the body directly?
0:10:51 > 0:10:54- Aphrodisiac foods - are full of nutrients...
0:10:54 > 0:10:57- ..so they may have had - a greater effect on people...
0:10:57 > 0:11:00- ..when malnutrition was common.
0:11:00 > 0:11:03- Eating nutritious, - 'aphrodisiac' foods...
0:11:03 > 0:11:08- ..may have done mind and body - a power of good and boosted libido.
0:11:11 > 0:11:15- Next, we discuss nature - and make some tough choices...
0:11:15 > 0:11:19- ..as we delve deeper - into the science of love.
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0:11:25 > 0:11:25- Subtitles
0:11:25 > 0:11:27- Subtitles- - Subtitles
0:11:37 > 0:11:40- Humans instinctively - search for a partner.
0:11:41 > 0:11:46- When we've found the right person, - we tend to stay together...
0:11:47 > 0:11:48- ..possibly for life.
0:11:54 > 0:11:57- It involves a huge investment - of time and energy.
0:11:57 > 0:12:00- What do we gain from doing this?
0:12:00 > 0:12:03- Do we see similar coupling - in nature?
0:12:03 > 0:12:07- Are human beings the only ones - who fall in love?
0:12:12 > 0:12:16- To find out more about love - in the world of nature...
0:12:16 > 0:12:21- ..I met the zoologist, Dr Gethin - Thomas from Swansea University.
0:12:24 > 0:12:27- Do animals fall in love - or is it unique to humans?
0:12:28 > 0:12:31- It's hard - to compare different species.
0:12:32 > 0:12:36- What happens between humans - is a very deep emotion...
0:12:36 > 0:12:39- ..so it's difficult - to find comparisons.
0:12:39 > 0:12:44- Several species mate for life and - have strong feelings for each other.
0:12:45 > 0:12:50- We can measure oxytocin, a hormone - released between long-term mates.
0:12:50 > 0:12:54- This hormone is vital - to the bonding process.
0:12:54 > 0:12:57- We can measure its levels - in their blood...
0:12:58 > 0:13:02- ..and state that they have - strong feelings for each other.
0:13:02 > 0:13:06- How much of that is chemical - and how much is love? I don't know.
0:13:11 > 0:13:15- What animals we've seen today - mate for a long time?
0:13:16 > 0:13:20- Lorikeets. They live for years - and they mate for life.
0:13:20 > 0:13:25- They mate with one male or female - and that remains true for 25 years.
0:13:25 > 0:13:28- The species - with the longest lifespan...
0:13:29 > 0:13:33- ..and who rear their young - until they reach maturity...
0:13:33 > 0:13:37- ..are the species - who mate for the longest time.
0:13:38 > 0:13:42- What are the advantages - of mating like this?
0:13:42 > 0:13:44- Reproduction is a risky process.
0:13:45 > 0:13:49- You never know how compatible - your partner's genes are.
0:13:49 > 0:13:54- If they're too similar, - it's detrimental to the offspring.
0:13:54 > 0:13:59- If they're too dissimilar, you can - be reproductively isolated...
0:13:59 > 0:14:02- ..like between a horse and a donkey.
0:14:02 > 0:14:07- You want someone who's similar - but genetically dissimilar enough...
0:14:08 > 0:14:11- ..to give the offspring - the best chance of survival.
0:14:12 > 0:14:15- The best way to do this - is to form long-term pairs...
0:14:16 > 0:14:20- ..which can provide - shelter and food.
0:14:20 > 0:14:23- Animals form a strong bond...
0:14:23 > 0:14:26- ..increase their - offspring's survival chances.
0:14:26 > 0:14:30- Yes, and if it works - and the offspring survive...
0:14:30 > 0:14:35- ..they stay within the population - and evolve and adapt to it.
0:14:47 > 0:14:50- Love usually blossoms - from an initial attraction.
0:14:51 > 0:14:57- Each, for reasons which are hard to - measure, is attracted to the other.
0:14:59 > 0:15:01- What makes someone attractive?
0:15:02 > 0:15:06- Is there such a thing as someone - who's attractive to everyone?
0:15:11 > 0:15:16- To look closely at attraction and - how much control we have over it...
0:15:17 > 0:15:21- ..we held an experiment - with a group of Cardiff students.
0:15:21 > 0:15:25- We asked them to place photos - of female faces in order...
0:15:25 > 0:15:28- ..with the most attractive - on the left...
0:15:29 > 0:15:32- ..and the least attractive - on the right.
0:15:37 > 0:15:41- We only gave them ten seconds - to put the faces in order.
0:15:44 > 0:15:47- There's no correct - or incorrect order.
0:15:48 > 0:15:51- We're only interested - in the students' choice.
0:15:51 > 0:15:54- She's attractive.
0:15:54 > 0:15:59- Like a computer, the brain works out - who's attractive and who's not.
0:16:00 > 0:16:03- It seems to be beyond our control.
0:16:03 > 0:16:06- Glasses. Oh, sorry!
0:16:08 > 0:16:12- When we see another face, the brain - reacts in a tenth of a second.
0:16:13 > 0:16:17- So quickly that the part of the - brain which deals with logic...
0:16:18 > 0:16:21- ..has no time - to influence the decision.
0:16:22 > 0:16:26- I don't like the red hair. - I like the more natural look.
0:16:26 > 0:16:31- She's really attractive. - Blonde hair and blue eyes.
0:16:31 > 0:16:34- These two look like models.
0:16:34 > 0:16:36- I like blondes.
0:16:37 > 0:16:40- They repeated the exercise - with male faces.
0:16:42 > 0:16:44- Again, a pattern emerges...
0:16:44 > 0:16:47- ..and some faces - are preferred to others.
0:16:48 > 0:16:52- Interestingly, the men and women - chose similar orders...
0:16:53 > 0:16:55- ..and they did it in quick time.
0:16:55 > 0:17:01- This suggests our brain responds to - a general idea of attractiveness...
0:17:01 > 0:17:04- ..a short space of time - after seeing another face.
0:17:04 > 0:17:07- We have no control - over this reaction.
0:17:09 > 0:17:12- Most of us tend to favour - symmetrical faces.
0:17:12 > 0:17:17- The brain calculates the distance - between the facial features.
0:17:17 > 0:17:19- The eyes, the nose and the mouth.
0:17:19 > 0:17:24- In the ideal symmetrical face, - the distance from nose to chin...
0:17:24 > 0:17:28- ..is 1.5 times - the distance between the ears.
0:17:29 > 0:17:32- We tend to seek - a symmetrical body too.
0:17:32 > 0:17:36- We compare a man's shoulder width - with his waist size...
0:17:36 > 0:17:40- ..and the width of a woman's hips - with her waist - her curves.
0:17:41 > 0:17:45- This symmetry is a sign that - a person has grown and developed...
0:17:45 > 0:17:48- ..that they're healthy - and have good genes.
0:17:49 > 0:17:53- These features - would have been vital in the past...
0:17:53 > 0:17:58- ..when raising healthy children - was crucial to human survival.
0:17:58 > 0:18:00- This instinctive reaction...
0:18:00 > 0:18:04- ..still influences - what we find attractive today.
0:18:05 > 0:18:08- Love at first sight - can last a lifetime.
0:18:08 > 0:18:10- What happens when we fall in love?
0:18:11 > 0:18:14- Scientists have separated love - into three stages.
0:18:14 > 0:18:18- To find love in the first place, - we must leave the house.
0:18:18 > 0:18:22- The hormones - testosterone and oestrogen...
0:18:22 > 0:18:25- ..fuel this drive to find a partner.
0:18:25 > 0:18:29- Once we find someone we like, - we're infatuated with them.
0:18:29 > 0:18:33- During this stage, - we tend to lose ourselves.
0:18:33 > 0:18:37- We struggle to eat or sleep, - we shun our family and friends...
0:18:37 > 0:18:42- ..and want to spend all our time - with the new person in our life.
0:18:42 > 0:18:46- All our focus, thoughts, time - and energy is on our new partner.
0:18:47 > 0:18:51- It can't last because - we can't get much done in stage two!
0:18:51 > 0:18:55- After a year or two of infatuation - comes stage three - attachment.
0:18:56 > 0:18:59- After the excitement - of finding a partner...
0:18:59 > 0:19:03- ..we decide to commit to that person - and things settle down.
0:19:04 > 0:19:07- Chemical changes - help us form long-term bonds...
0:19:07 > 0:19:10- ..which prepare us - for child-rearing.
0:19:10 > 0:19:12- This may be true love.
0:19:18 > 0:19:20- The body sends us out - to look for love...
0:19:21 > 0:19:24- ..but the way we do this - is changing.
0:19:24 > 0:19:28- More and more of us are now - finding love on the internet.
0:19:29 > 0:19:30- According to one study...
0:19:31 > 0:19:35- ..one in five new relationships - starts on the internet.
0:19:35 > 0:19:39- That's likely to increase - over the coming years.
0:19:39 > 0:19:43- What are the advantages - of finding love in this way?
0:19:43 > 0:19:47- Catrin and Aron met on the website - Pishyn.com over ten years ago.
0:19:49 > 0:19:52- They're now married with children.
0:19:52 > 0:19:56- I met them in Caernarfon, - where they had their first date.
0:19:57 > 0:20:02- How did people react when you - first told them you'd met online?
0:20:04 > 0:20:07- The reaction was pretty positive.
0:20:07 > 0:20:12- When you want to buy a car, - you go online and do some research.
0:20:12 > 0:20:15- You make a list - of the features you want...
0:20:15 > 0:20:18- ..and you take the car - for a test drive.
0:20:18 > 0:20:21- Why not do that - with more important things?
0:20:23 > 0:20:26- In years gone by, - people corresponded by letter.
0:20:26 > 0:20:28- It was romantic.
0:20:28 > 0:20:32- By writing and reading, - you learn a lot more about someone.
0:20:32 > 0:20:36- In a way, exchanging a number - of emails with someone...
0:20:37 > 0:20:39- ..is quite old-fashioned.
0:20:39 > 0:20:44- Certainly, the process of learning - about someone's character...
0:20:44 > 0:20:48- ..is far more intense than when you - meet someone in a pub or a club.
0:20:49 > 0:20:54- Following that initial contact, - why did you meet face-to-face?
0:20:55 > 0:20:58- There was something there. - We clicked.
0:20:58 > 0:21:01- Just like when you meet someone - in the flesh.
0:21:02 > 0:21:04- She ticked all the boxes.
0:21:04 > 0:21:08- I knew what I wanted and I - didn't want in a potential partner.
0:21:10 > 0:21:14- The two of you were attracted - to each other's personality...
0:21:15 > 0:21:17- ..rather than a physical attraction.
0:21:18 > 0:21:23- Definitely. There were no photos, - so I didn't know how Aran looked.
0:21:23 > 0:21:26- When we met - in the doorway of this pub...
0:21:26 > 0:21:28- ..it was quite fresh.
0:21:29 > 0:21:33- That mental attraction - gave us a foundation...
0:21:33 > 0:21:37- ..then you either get that spark - that goes with that or you don't.
0:21:38 > 0:21:40- That spark was there, wasn't it?
0:21:40 > 0:21:43- After that first date...
0:21:43 > 0:21:48- ..would you have believed - you'd be married for over ten years?
0:21:48 > 0:21:52- When I left this pub, I texted - my brother to come and pick me up.
0:21:53 > 0:21:56- When I got into the car, - I told my brother and his wife...
0:21:57 > 0:22:00- ..that I'd just met - the man I was going to marry.
0:22:01 > 0:22:06- Do you think more people in future - will meet by using technology?
0:22:07 > 0:22:12- I think so. It's becoming more - normal and more socially acceptable.
0:22:12 > 0:22:16- In the future, we won't ask - whether or not a couple met online.
0:22:17 > 0:22:20- People will stop seeing a difference - between the two.
0:22:20 > 0:22:25- It prepares the ground because - you know there's a connection there.
0:22:25 > 0:22:30- The brain plays an important part - in physical attraction.
0:22:30 > 0:22:35- When you meet - and there's a spark there too...
0:22:37 > 0:22:39- ..you know things seem promising.
0:22:42 > 0:22:44- We're mesmerized by love.
0:22:45 > 0:22:49- It's more than a feeling - it's an - instinctive biological force...
0:22:49 > 0:22:54- ..which has an impact on our - behaviour, our mood, our mindset...
0:22:55 > 0:22:56- ..and even our decisions.
0:22:57 > 0:23:00- Love begins with - an instinctive attraction...
0:23:00 > 0:23:05- ..and it develops in stages, led by - chemical changes in the body...
0:23:06 > 0:23:12- ..as we form and build a bond which - will change the way our brain works.
0:23:13 > 0:23:17- Love makes it possible - for us to mate for a long time...
0:23:17 > 0:23:20- ..have children - and keep our species thriving.
0:23:20 > 0:23:23- Love may be a chemical reaction...
0:23:23 > 0:23:28- ..but the pleasure, infatuation - and contentment of being in love...
0:23:28 > 0:23:31- ..is something personal - for all of us.
0:23:31 > 0:23:34- It's hard to imagine - a world without love.
0:23:49 > 0:23:52- S4C subtitles by Eirlys A Jones
0:23:52 > 0:23:52- .