Almost one in 10 Britons say they buy clothes online just to post an image on social media, before sending them back immediately for a refund; among those aged 35 to 44, this rises to nearly one in five.

Barclaycard, which commissioned the new research, says this trend to “snap and send back” is on the rise, in part thanks to the hashtag “outfit of the day” (#OOTD). Here, Instagrammers upload a picture of themselves to showcase what they are wearing – in a bedroom, on a beach or on the streets – and the hugely popular hashtag has more than 2m posts.

What does this tell us about ourselves and our clothes? For Caryn Franklin, fashion commentator and an activist for sustainable fashion, the answer is: nothing good.

Fashion at its best, she says, gives us the chance to explore and create our identity, to figure out who we want to be. She has seen this from early in her career when she worked as a personal stylist: “I saw beautiful miracles at the mirror, as ordinary women witnessed their indisputable magnificence. Clothes are firmly embedded in our emotional experience of ourselves. We dream of who we wish to be and feel better connected to that person through the garment we inhabit.”

In the age of Instagram, identity has become a brand, and jumping on the high-speed buy-and-return bandwagon has created “an instant, disposable self”, she says. “My clothes are like longstanding loyal friends. They make me feel joyous, brave, excited. Does buying, Instagramming and returning an entire outfit in a day provide us with any but the most superficial feelings?”

Franklin remembers a pre-digital fashion experience that involved yearning for that longed-for dress or coat or pair of shoes, saving up and finally making the trip to the shops before rushing back to enjoy the new purchase.

“The experience of buying, bonding with the newly acquired item and returning home for the subsequent styling session would signal the beginning of yet another fulfilling relationship. All this, without cameras.” Now, she says, the OOTD hashtag, among others, has encouraged “a combination of the heady alchemy of narcissism and dysfunctional consumption”.

This is symptomatic of our problematic relationship with fast fashion, she says, and has implications for the environment and the economy, as well as for our souls. It is not sustainable. In what she calls “a transparent illustration of the reduced value of their mass produced product,” having secured higher and higher sales, online retailers may now be panicking at high-level returns. She says: “The fashion industry has lost its currency. Some might say our industry deserves no mercy, having been accused of so many wrongs akin to eating its own young. Now fashion is eating itself.”