When ～がります is used instead of ～がっています, it expresses the third person's tendency to want (to do) something, or to demonstrate certain emotions under particular circumstances.
弟は、おかしを見ると、いつもほしがります。
Whenever my younger brother sees sweets, he wants some.
いもうとは、デパートへ行くと、いつもおかしを買いたがります。
When my younger sister goes to a department store, she always wants to buy sweets.