It may sound like I’m trying to teach you to suck eggs, but there is a very specific mode when it comes to sitting in meetings or formal environments. Almost everyone knows not to slouch, although over long periods of time it can be easy to let your body slip down the chair – before you know it your neck is where your bum should be. The reasons for not doing this should be obvious – it shows a slovenliness, a lack of interest in what’s going on and your personal impact.
People only really slouch in a comfortable environment – it’s rare to see it in formal settings unless it’s out of habit or the sloucher has forgotten where they are. But what you do see more often is a kind of counter-slouch; people so aware of their posture they sit, poised to leap out of their chair at any given moment. This is especially common in interviews, with candidates keen to show they’re not slouching, they sit uncomfortably rigid, looking like they’d be better off standing up rather than sat down. This doesn’t look as bad as slouching, and people will always like this on some level because it displays a great deal of effort and a desire to impress, but it does not look natural, or comfortable, and looks a little fake.
The best way to sit is naturally, with your back up against the chair, resting against it most of the time, legs bent at about ninety degrees and feet on the floor, if they’ll reach. Simple and comfortable for the most personal impact.