People say this for a reason. Not because there are no selfish adults (certainly not true), but because empathy is developed over time as experience makes the picture bigger. You can speed this process up by showing them a bigger picture.One way to do this is to ask them to tell you about issues with friends and teachers. Ask questions about how the other person may feel and think. Soon, when looking for answers theyu2019ll start to instinctively consider the opposite viewpoint.Another way is to talk about broader issues with them. Ask them to come with you to volunteer, watch documentaries with them, give money to the homeless when you are out with them. As another answer said, teach by example. Perspective and experience help people learn about others problems. And the more you know, the more you tend to care.