In all reality, the generations should now be about 30–40 years. Because people are indeed living longer, and waiting longer to have kids. Because people are waiting longer to have children, and medical technology is getting better, so people can have children later in life. The 30–40 years is when people have kids (at ages 30 to 40). Deciding when one generation is ending and another beginning should be left to the genealogists, not the media or the scientists. BUT, if you must see proof as to what I've been speaking about, here's an article from a sociology journal stating what I've been saying about 30 YEARS: https://www.jstor.org/stable/587038