When you’re riding solo, it’s normal to hug the inside part of the lane when making turns.  In the video below, you’ll see this demonstrated.  The white lines indicate where the rider’s looking throughout the turns.

When riding in a group, however, you ride in a staggered formation.  Many riders have the tendency to still hug the inside of the lane when making a turn.  Doing this breaks the 2 second separating the rider directly behind you has with the rider directly ahead of you.  In the following clip, you’ll see all riders except the fifth in the formation are keeping to their staggered formation through out the turn.

Keeping in staggered formation keeps everybody in the group safer.  If you find you are unable to keep in your tire track when making turns, it’s suggested that you ride at the back of the group, and take the turns slower but maintain your position in the lane throughout the turn.  Once back on a straightaway, you can regain the two second gap.