CHRISTMAS has changed.

Only a few decades ago it still came in huge parcels: flat and rectangular like a train set, lumpy and irregular like a bike, or boxy like a flat-packed Barbie doll's house. Greedily, these gifts would be unwrapped and sometimes put into action straight away, as whole Lego cities were collaboratively constructed around the floor. But these days the boxes are smaller, slimmer and more streamlined. For the most part, whether the receiver is adult or child, Christmas comes bearing a screen, or something that links up to one.

According to the sales figures and wish-list statistics, on the first day of Christmas this year, true loves will be sending an Xbox One, a PlayStation 4, an Aldi Medion Lifetab, a Tesco Hudl, an iPad, a Google Nexus 7 tablet and a Samsung Galaxy Tab 3. Across the land, when these presents are opened, people will be switching on, charging up and logging on.

Christmas has long been idealised as a time of coming together, particularly for families. But that coming together has changed. We no longer all sit watching the same television shows in the living room. Instead, according to an Ofcom study published earlier this year, we are connected to multiple media platforms, each staring into our own screens. This Christmas Day, not only will many of us be giving the gift of that connectivity, but we will be living it.

In some households, this will mean a stream of parental barks telling the kids to switch off the Nintendo DS and come to the table, or that there will be "no more screen time till after tea". Others will give in to full tech immersion, surfing their way through the festivities by communing with distant friends or virtual game companions. How you feel about this vision of Christmas probably depends, in part, on how old you are. To some of us, it seems like a Christmas that is more together; to others, less.

In her book Alone Together: Why We Expect More From Technology And Less From Each Other, sociologist Sherry Turkle suggests our increasing use of technology is making us more distracted and less able to be intimate with those around us.

This technologising of Christmas, and our lives, can be charted through the list of the most popular gifts that we have given over the years. In 1980, when I was 10 years old, it was a Rubik's cube. One year later it was a Lego train set and the year after that, a BMX bike. The list took a dramatically different course around a decade ago, when it veered away from toys towards gadgets and consoles, beginning with the Nintendo DS in 2004, followed by an Xbox in 2005, and a whole raft of other top tech toys, including an iPod touch, a PlayStation 3, a Wii, and a Kindle Fire.

Like many parents, I have been stewing over whether to give the gift of technology to my children for the past few years. I have two sons, aged six and four. They, of course, like many kids, want their own screens. According to a recent survey, three-quarters of children want a technology gadget for Christmas. I know this desire, I have seen it written into my sons' Christmas lists: Wii first, followed by Nintendo DS. My elder son sighs wistfully when he talks of the Wii. I tell them Santa doesn't always bring children all the things they want. So far, the boys are getting tennis racquets. Those were also on the list, but near the bottom.

So, why not give them what they want? Am I causing disappointment pointlessly? Financial cost aside, why hold out when their future is clearly going to belong to a generation of digital natives? The problem is, like many parents, I have the fear. Partly it is inspired by some of the stories about the effects of prolonged use of technology, of "too much screen time" on a generation of developing children. Baroness Susan Greenfield, professor of pharmacology at Oxford, for instance, declares that she is "worried about what amount of time a child spends in front of a screen. I feel they are not living a full life, they are living a 2D life". Meanwhile, psychologist Dr Aric Sigman argues that computers should be banned until children reach the age of nine.

But my fear is also triggered by the sinking feeling I've got from seeing kids at parties or other social occasions, hunched over their individual Nintendo DS, barely looking up for a moment.

How much access children should have to technology has become one of the most polarising issues in modern parenting. I have heard of families who have holidayed together and found their trip disintegrate into arguments over the issue of how much time the kids were allowed on their gadgets - or whether indeed they should have brought them at all. Some of this is just a clash of parenting-style - between those who want to set strict boundaries, and others who are more laissez-faire - but some of it is also down to how at home with technology parents are. Among my friends, those who work in technology appear to be the most relaxed about letting their infants tinker on iPads.

Scientific research on the subject is in its infancy, and the existing research is contradictory. If you want, as Sigman does, to suggest that "screen time" is bad for children, you can find a few pieces of research to support that view, which show correlations with attention deficit, or with obesity. But there is other research that suggests possible benefits: correlations, for instance, between computer skills and better IQs. The debate has become polarised, propagandised, reduced to a tit-for-tat battle in which one side calls out its fears, while the other accuses them of doom-mongering.

It is a hugely emotive subject. When Turkle talks about the way phones and gadgets interrupt the sacred space of family mealtimes, the implication is that they play some part in the breakdown of family life. People talk of phones and iPads being used as "babysitters", with the implied accusation of parental neglect. The problem is, or course, that most weary, distracted parents know that this is true. Technology is our favourite, cheap childminder. We hand over our laptop to distract our child while we get the tea ready, then get angry when the food is on the table and yet they don't want to peel themselves away.

Our use of technology is continually being quantified, yet we still have very little idea of what it is doing to us. A news story may tell us that adolescents spend 7.5 hours online these days and about half-an-hour less of time with family members, but we don't know if these factors are connected. And while there have been studies that suggest technology is making us more isolated, there are others which show the opposite. One 2007 study from Michigan State University found that Facebook users had more social capital than abstainers, and that the site increased measures of "psychological wellbeing", especially in those suffering from low self-esteem.

For Helene Guldberg, author of Reclaiming Childhood: Freedom And Play In An Age Of Fear, the problem is that, in many cases, "the researchers are looking for evidence of harm, and if they look hard enough they are bound to find correlations between time spent on screen-based technologies and some negative phenomena. It would be interesting to see more qualitative research on how children and young people use screen-based technologies and why some find them so enticing. In my experience there are some children who can take it or leave it, and others who would stay glued to the screen for hours if given free rein."

Even as these iPads and Xbox Ones are shifting from shop shelves, there is a backlash against technological toys for children. A plethora of articles across the web jokingly gives good reasons not to buy an iPad for your kids for Christmas. Project Wild Thing, a campaign to encourage outdoor play, suggests an alternative "top toy for Christmas", a stick, and encourages the swapping of "screen time" for "wild time". Of course, it's possible to have sticks as well as screens - just as many children get that old-fashioned outdoor present of a bike as well as an iPad. It is not an either/or. I was recently impressed, for instance, with the way the outside nursery in Glasgow's Pollok Park incorporated the use of technology into its outdoor play.

Like alcohol units, screen time has become one of the ways we divide up life, putting limits on the things we think are not so good for us. These days parents seem to approach the rationing of screen time in the same way they do sweets; using it also as reward and treat. The American Academy of Pediatrics advises that children have less than two hours of screen time a day - and no digital media at all for the under twos. Yet a survey published last week showed that in the UK, around half of two to three-year-olds -dubbed "iTods" - are playing on tablets.

So great is the urge to find ways to restrict this aspect of children's lives that there are even apps that will switch the machine off when the allotted time is up. Many tech advocates encourage such limits as part of the general boundary-making of parenting. As Guldberg points out: "We need to limit it just like we put limits on what and when children eat, how often they wash and so on. Children need to learn that they cannot always have what they want when they want it."

Meanwhile, there is a whole tranche of research claiming that technology can be good for children. But much of it suggests that this is only when used in interaction with real-life scenarios, in groups or with parents engaging in the play too. This is not technology as babysitter, but as part of the general hard work of coaching and educating. Frankly, it sounds a bit of a slog. Restrictions on screen time? Coaching? Wouldn't it be easier to just leave them to fight their way through a game of Moshi Monsters Top Trumps?

Not everyone, however, believes that technology is something that we digital foreigners need to coach the natives through. Helene Guldberg believes we need to be "more relaxed about letting children explore technology on their own. The world is changing: we are living in a world of social media and instant access to information. We cannot - and should not - turn the clock back. The problematic aspects of new technologies are also what is really positive about these technologies."

Without doubt we humans are changing, just as we changed centuries ago with the print revolution, just as we changed when we moved to cities and started working in factories rather than on the land. People once fretted over what the telephone and the radio would do to us. In 1835, the American Annals Of Education declared that the "perpetual reading" of novels "inevitably operates to exclude thought, and in the youthful mind to stint the opening mental faculties, by favouring unequal development. No-one can have time for reflection, who reads at this rapid rate".

Bound up in the question of what I give my kids for Christmas are all my personal anxieties about technology and the brave new digital world that my children will have to make their way in. Of course, that journey for them has already begun, and without me deliberately leading them there. It began when my elder son first started to look at photos on my phone, then found his way to the games apps. It continues now, as I allocate both my boys short stretches on the phone or laptop. We don't talk about screen time, but it already punctuates our lives.

Technology crept in long ago. Yet still I fear the Wii or the Nintendo DS, and all that might follow after that. I worry about what it will do to my family. I fear seeing their eyes locked on a screen when I long for them to be locked on me, or on each other. Will technology make my kids lonelier or more isolated?

Having read sections of Alone Together, I'm inclined to believe it has already. Turkle's research found the problem for children is not just their own prolific use of technology, but that of adults. Many of the teenagers she talked to spoke of how their parents were often distracted by phones, and how they felt they came second to the bright, bleeping lure of a screen.

The best gift we can give our children for Christmas? Not a new iPad or console, but the switching off of our own phones. Perhaps, this year, I'll just wrap mine up in festive paper and put it away for the day.