I think he's going through an awkward phase. He's no longer an adorable toddler, but isn't quite a gangly little boy.
I can't disagree, however, with @Westiepeach. A lack of fresh air, good food, exercise, and mental stimulation is pretty tough for a kid.
The script has really flipped between him and Izzy. A few years ago, Spurgeon was a cute, confident kid playing on a slide with his nervous, desperate-to-please cousin. Now, Izzy is relaxed and happy and Spurgeon looks lost and confused and desperate for attention.