The Psychology of a Messy Room

There are various factors which contribute to messy rooms

pack-rat-ism - the accumulation of many objects
oblivion -being unaware of surroundings or tuning out the environment
busy-ness - rushing off in the middle of things and not having time to clean up later
distraction - being drawn away from a task, then starting to clean and being distracted again
convenience - liking to have everything close at hand
multi-tasking - starting many projects at once and working on them simultaneously
stickynotes - leaving things out to remind you to finish them

The traits most likely to be correlated to messy rooms are F, P, and N.

Fs are more likely to accumulate useless sentimental items, things they simply liked though they don't know what to do with them. They value the presence of many items, and the overall feel of the room based not on what is functional and efficient, but what conjurs good feelings. This allows some things which may seem to just add clutter to not be considered 'in the way' by the F because it's mere presence is its purpose. They are also likely to choose to spend their time doing things they feel like doing, which may not be mundane attention to clean up. However, if they realise that having a clean room will make someone else feel better, they are likely to bite-the-bullet and take care of it.

Ps have no problem leaving things open-ended, and thus have a tendancy to start many projects and work on them off and on depending on their mood, time, and supplies. Because none of the projects are actually finnished, they don't want to put them away because that would be unessessary bother, and would make it even less likely for them to get back to it and actually finish it. They don't tend to divide projects into distinct steps which they work on in planned segments of time, like Js do, and so the 'finished-clean-up' bell never rings for them. They also don't have a high value of order or structure and probably don't have a specific place where they feel each item belongs, thus wherever it is is where it should be, especially if where it is is within convenient reach. They like to let thoughts and ideas brew for a long time before actually choosing what to do, and leaving the things out that they're thinking about aids in this process of slow-brewing. This slowness to finalize, also means that their projects are in the works for much longer than a Js would typically be. They are less likely to care about social expectations to keep things orderly as well, so they don't feel pressured to get things out of the way in order to maintain their reputation.

Finally, the N's inward focus on thoughts makes them prone to ignoring their physical surroundings. An N is likely to be so absorbed in the world of ideas that he simply doesn't notice what is immediately arround him, shutting off his 5 senses to better tune into his 6th. Even if an N is aware that things are getting messy he is unlikely to place such a boring, and fairly meaningless, task high on his priorities, allowing himself to remain focused on thinking rather than shifting into the realm of action. Concerned with contemplating deeper meaning in life he freely procrastinates doing everyday tasks which seem so unimportant in the large scheme of things, and which are certainly less fullfilling to him.