A great number of people are of the opinion that youngsters are more selfish nowadays,they just care the thing what's happened to them.They just care about themselves.
You should use period to separate those two sentences.
However, I strongly contend that youngsters nowadays are more aggressive to help others.
I think the word "aggressive" is improper. You can replace it for "willing".
The most critical reason for such an assertion is that nowadays, young people are more well-educated, knowknowing not to take things for granted, and should help others when they are in need.
Take as an example, Life science, which is a kind of major which cuts across the boundaries of many different disciplines.
Take students from life science major for example.
Those students who major in life science have to learn various subjects such as biochemistry, virology and posology. Although they are not doctors , studentsthey still can use this academic knowledge to teach public how to improve their immune system and recognize the pathogenesis.to teach people how to stay healthy.
To further elaborate, youngsters nowadays are more carecares more about social issue.
The social media enables youth to pay attention to needy people. For example, if a disadvantaged group asks for help by posting on TweeterTwitter , the information may be forwarded and circulated. Thereby, youngsters, one of the main users of Tweeter, are more willing to help the group. Therefore, with the power of the technology such as internet, people more tend to help others.People tend to help others more.
Overall, I don't think that your first reason is strong enough. I can't see strong relevance between education level and the willingness of helping people. There are still high-educated people who are indifferent. Maybe you can say that educations now stress more on helping people.
Hope this help:)