Teenagers keep their distance in the cautious new world of dating and sex

Last year, one study on human interaction stopped us in our tracks. Despite sexual liberation, contraception, dating apps and social media, young people are having less sex than any generation in 60 years.

This dramatic shift in behaviour is best researched by American psychologist Jean M Twenge and last week she released new data to pin the blame on the smartphone -with teens now choosing the superficial interaction over real life encounters.

But if parents think they can take comfort in the thought that less sex somehow translates into a more wholesome approach to dating, then think again.

Aoife (18) is a pretty, smart and outgoing young girl. But she is confused by elements of the new sexual and relationship mores that she, like all late teenagers, are now desperately trying to navigate.

For a start, the art of flirting and dating has become tediously drawn out, often lacking boundaries, exclusivity and any clear direction.

The days where sexual interest was sparked from across a room and quickly followed by the butterflies of a first date are long gone. Today's teens have become so reliant on screen time that they first need a phase of long term ''talking'', usually confined to text, before they ever meet face to face.

"You could talk to a guy for a long time over WhatsApp, hoping that you would get a date. It could take a month or even a lot longer before that happens," says Aoife.

Twenge calls them the ''iGeneration''. Born between 1994 and 2012, their entire world is in their pocket. The phone offers convenience -but, more importantly, security and the ability to save face.

Given the option, teens will naturally choose a world where they can filter their image, express emotions more casually through emojis and take time to draft the perfect response - which means they can always keep a safe distance from the people they are chatting or flirting with.

But all of this comes at a price: real intimacy is being sacrificed for control.

As Tim (19) says: "Expressing your feelings face to face to a person is now seen as a milestone in a relationship. I can count on one hand the number of times that I have had to do that. And it felt terrifying."

Focusing on teens in the Untied States, Twenge illustrates how the world of the next generation is shaping up.

Since the smartphone arrived in 2007, time spent hanging out with friends has plummeted - along with going on dates and having sex. Similarly, after 2007, loneliness among teenagers has risen dramatically, as have anxiety and sleepless nights.

With body language redundant in the early stages of courtship, teenagers predominantly gauge whether a person likes them based on their social media activity. "You know he's into you if he 'likes' your photos on Facebook and he takes a general interest in what you're doing online," says Aoife.

And thanks to new sexual liberations, when teens eventually start dating this phase can drag on for months before two people are exclusive. "People can often date for nine months or a year before they are officially 'boyfriend and girlfriend'. To get to that stage, you have to be in it for the long haul," she laughs. But in the meantime, she says, feelings can get hurt.

"If you are on a night out and you have been talking with or dating a guy for a while and then they go off and get with someone else, you can feel uncomfortable but you can't really say anything. You would have to try and play it cool."

You mean the guys are still playing the field, while dating a girl?

"Yeah, I guess. Girls are more emotionally involved and they want relationships but in general guys are just out there enjoying themselves and there's no real definite boundaries any more. You just have to figure it out as you go along.

''Everything is so much more open these days in terms of 'what goes."

Ben (20) agrees that traditional rules no longer apply: "It's hard to know what counts as 'dating' these days. I've had four exclusive relationships in the past three-and-a-half years but none of them lasted more than six or seven months. In that time we never really acknowledged each other as boyfriend and girlfriend except when badgered by friends.

''I certainly never had any desire to bring them home to my family."

Ben says the change in dating habits is a result of how much more widely connected people are through social media: "It's relatively easy nowadays to maintain distant 'token' relationships with any number of girls so there's no pressing need to commit to one the way there was in the past.

"Meet a girl at a club, add them on Facebook or any other platform and you have them in your back pocket forever, so to speak, with both parties able to keep loose tabs on each other so there isn't any real awkwardness starting up a connection again some time down the line."

He explains that the breakdown of marriage among their parents' generation has also given today's teens pause for thought: "A stigma has been building around relationships for a few generations now.

"Not to be overly dramatic about things, but with divorce as widespread as it is and there being so much general emphasis in the modern world on the pain and stress involved in failed relationships the idea of jumping eagerly into one is a lot less appealing.

"It's gotten to the point where I could probably count with my fingers the number of couples I know from the generation above me who've maintained genuinely successful long term relationships worthy of emulation. Those aren't good enough odds to be committing too one without serious caution."

Aoife says girls are now feeling more able and comfortable with playing the field too, which sometimes doesn't sit well with proud or territorial guys: "Which is funny because guys sometimes have double standards. They can go off and score a few different girls and they sometimes just expect the girl to not see anyone else. And when it does happen, the guy isn't happy. But sometimes, when they don't know it doesn't hurt them."

Such is the confusion that a new list of terms is helping people figure out where they stand.

Ghosting, for example, is driven by technology's capacity to anonymise, and it defines how people can step straight back into the darkness without a word of explanation or hassle.

Another trend, ''cushioning'', avoids the emotional fall-out of relationship breakdown by keeping several guys or girls on the go at once. Similar to a zero hours contract, it says ''you do the job or I have others who will fill your place''. ''Benching'', on the other hand, means you can keep someone in the wings, while you date around to see what else is out there, while ''breadcrumbing'' happens when you send someone the odd text to maintain their interest.

Social media stalking has also become normalised, even if people don't publicly admit it.

This happens when you lurk at the edge of someone's social media page to see what they are up to.

How do you know they are there? The Linkedin app shows profile views, while Snapchat Stories - which are short self-made videos - allow you to see who has watched your content.

But with the internet providing so much more freedom, are the younger generation happy?

Tim admits that even young guys are finding the freedom can lead to a certain kind of madness.

"We have a new sense of entitlement that comes with this freedom that leads us to bend the rules and I guess we are more likely to branch out because we can get away with it.

''But to say guys are completing enjoying the culture is overstating it a little bit."

Tim believes so much choice "brings with it a sense of boundless curiosity".

"It means you are constantly on a quest for 'the one' or to attain what is the 'optimal' person out there and if you settle you feel like you are giving up the chance to see what else is around."

He says: "All of this can look like a lot of fun from the outside but it can take its toll long term because it's self-defeating.

"No one person is perfect. Feelings go up and down and you have to work at a relationship if you want to maintain something long term.

"I know plenty of guys who are outwardly celebrating being able to be with a whole bunch of people but deep down, if you got them drunk and talking, you'd find they don't necessarily feel that way.

"Still, people are too afraid to chose just one person. It feels too much like the end of the show or an adventure.

''It's become a lot harder for a lot of people to decide that one person alone is ever enough."