Repeating outfits: in. People pleasing: out. Paying with cash: in. Photo dumps: out. A quick trawl through social media and it is evident that for 2025, traditional new year resolution lists are out and “ins and outs” lists are, er, in.

These listicles do exactly what their title suggests, demarcating everything from specific items of clothing to wider food trends and dating rules into two opposing grids. On TikTok the hashtag “ins and outs” has quickly acquired more than 44,000 posts. Unlike new year resolutions, which tend to be specific goals, “ins and outs” act as a barometer of cool.

So why are they spamming our timelines?Liza Walter-Nelson, chair of the British Psychological Society’s Division of Occupational Psychology, says part of their appeal is they don’t require much effort to pull together. “They could be a fun and engaging way to share personal goals or societal critiques, or they could be entirely performative for likes and attention grabbing,” she says. In short: “They are an easy win.”

Some lists appear as screenshots taken from the user’s iPhone Notes app, which create a sense of intimacy. Others are carefully placed over an inspirational image or video. The fashion influencer Camille Charrière’s in list includes visibly worn clothes, hard conversations, library cards and dancefloor snogging, while her out section spans it-bags, drunk texting and airplane meals. Meanwhile, the Substack writer Jess Graves is championing paywalls, pavlova and the colour purple (“especially lavender”) on her newsletter The Love List, while Vogue has declared themed weddings, photo booths and buttonhole flowers as over. The brat mood of 2024 is showing no signs of quiet quitting, with dancing and cigarettes appearing on scores of lists, while references to chatGPT and billionaires on out lists hint at a wider mood among millennials and gen Z.

Listicles are obviously not a new concept. In 1978, the Washington Post’s fashion editor Nina Hyde launched The List, an annual feature suggesting in its inaugural year that funk, Gloria Steinem’s wire-rim glasses and Farrah Fawcett curls were out while ties, bosoms and loose, mannish jackets were in. Today anyone with a social media account can be a tastemaker and propose an inventory of what they deem to have cultural cachet. Many of these lists go viral, tapping into a wider social media flex culture.

Walter-Nelson describes today’s iterations as “largely subjective, reflecting individual opinions rather than any kind of objective data or analysis of objective data. They seem to blend personal preferences with humorous observations and so they are more of a cultural commentary as opposed to the original, which was a researched reflection of trends.”

Less stringent than resolutions, “ins and outs” focus not so much on what you need to achieve over the next 12 months but more so on what brings you pleasure. For some that could be hitting 10,000 steps day; for others it is a leisurely morning bath, or salt and vinegar crisps. Perhaps these little nuggets of insight are fuelling interest in the trend.

While some lists are self-deprecating, others come with a heavy side of sneer. Walter-Nelson says it all comes down to tone and sentiment. “Judgmental or exclusive ‘ins and outs’ lists can intensify upward social comparisons, where individuals see themselves as falling short of what’s in. This can lead to feelings of inadequacy, envy and reduced self-esteem.”

However, with numerous corporate giants attempting to join in by posting their own micro trends on LinkedIn, perhaps it’s not long before “ins and outs” are officially out.

What’s hot – and what’s most definitely not – this week

Going up

Compression boots | Dua Lipa’s wellness tip for 2025. Like a foot massage but, at £549, a bit more spenny.

Arm parties | The 2010s trend for bracelet stacks is back. See Kieran Culkin at Sunday’s Golden Globes. Very post-Swiftie. Very chaotic. Very 2025.

Skinny jeans | Trend forecasters keep trying to make them happen. Maybe this will be their year?

Going down

Murder on the Dancefloor | Finally retired thanks to Father Figure in Babygirl’s dancing scene.

Raw | Raw milk? How about raw water? No, thanks, we live in the UK.

Gen Z | Welcome to the world, gen Beta. We can’t wait to hear your thoughts on side partings and ankle socks.

Chloe Mac Donnell, deputy fashion editor, solves your wardrobe dilemmas

Q: I never work out but in the hope of easing nagging back pain I have signed up to a weekly reformer pilates class. I need to buy leggings and some sort of a top. I don’t want to wear a crop top. Could you share some suggestions? I’m 5ft 8in and usually wear a UK 12 – Liz

A: Starting a new exercise routine can be daunting, so it’s a good idea to wear clothes that you feel comfortable in. Leggings-wise, look for a high waist and full-length leg – you don’t want them to roll down while you are trying to master a shoulder bridge. I find an adjustable waistband tends to come loose no matter how tight it’s secured, so I’d opt instead for a compression-type band. Check out Vuoiri’s All the Feels leggings, which come in a range of muted colours. They are snug without feeling suffocating and skim over rather than cling to any lumps and bumps. For a cheaper option, M&S’s Goodmove line is great. A fitted tank or T-shirt won’t gape when you’re in a plank position. You could always wear one under a baggy T-shirt if you’re more comfortable wearing something loose on top.

Got your own style question? Send it to fashionstatement@theguardian.com.