Was this man only displaying manners because she was attractive?

I was standing in a que, and the women in front of me dropped a tin of Vaseline, the man swooped to the floor to pick it back up for her. He smiled and she replied with "thanks". She was pretty and young. Then I saw an elderly lady struggling with 10 tesco bags, while trying to pick up her purse which had fallen out of her bag. Not once did he offer her help. Not even when she had to resort to sitting on the floor to find her purse. Of course I helped best I could. But I thought it was a little unjust, or is that just the way the cookie crumbles?