"research has shown that people sleeping in an upright position have sleep that is poor in quality compared to those who sleep in a horizontal position"

That is "True".

There are various stages of sleep, one of them is REM or Rapid Eye Movement stage, when we enter this stage of active sleep, and our muscles lose tone, making it hard to keep up a seated position. Accordingly, when we rest upright, our necks tend to strain or drop to the other side, which can cause pain. There are other issues as well but this should also be noted that in certain conditions an individual needs to sleep in upright position.

elizabeth loftus conducted a study to observe the reliability of eyewitnesses during the 1970s. their baseline was to define how accurate are the recollections of eyewitnesses.

her studies do not support the use of eyewitness. loftus mentions in her work that we are not required to recall some experiences, meaning that rarely an individual eyewitness testimony is trustworthy. a good example is presented in her work, where all individuals watched a video and were than asked "about how fast were the cars going when they hit/smash? ". the testimonies changed based on the word she used to make the question (hit or smash), proving the fragility.