My first response to this is, assuming that time is linear, life IS improving. If we look back thousands of years - we see hordes of people attacking villages - raping, plundering, and pillaging others. We had the Huns, the Vikings, the Inquisition, and many others who constantly conquered and destroyed others. They burned people at the stake - for being "witches" or heretics of the church simply because they believed the earth was not the center of the Universe.
Moving forward in "time" - we see the massacre of Native Americans, slavery, no rights for women, blacks or other ethnic groups. Mixed ethnic marriages were not only frowned upon - people were attacked and discriminated against. We now have much more acceptance of others, more people have voting rights and are no longer treated as possessions or second class citizens. (It's not all perfect yet - but certainly better than it was.) Fewer people and countries are interested in our solving differences by going to war. The world no longer seems to have an issue with mixed relationships - they are now common place. We are much more aware of those who are suffering and struggling around the world - and often rush to help when they have experienced catastrophic events. We are becoming much more globally aware. Many are even realizing that animals have feelings, and often make a stand to protect those animals.
As hectic as the world might seem because we are going through changes - or "birth pains" - consciousness has evolved and is continuing to evolve. And we seem to be speeding up that evolutionary process. Science is discovering amazing new things about "reality." Intelligent, rational, respectable. and notable scientists are even discussing our potential to be immortal, to time travel, or to teleport - all things that were considered science fiction just a short while ago. It's exciting - to me anyway - to imagine what we might see in the future. There are no limits.
Some believe that reincarnation exists so that we learn and evolve, so that we become better beings or become more God-conscious.
However, IF- as quantum physics is suggesting - there is no such thing as time, that everything is happening simultaneously and in the present moment - that there is only NOW - then other lives might exist for our experience and enjoyment. We are just having experiences - whether to learn something different, to experience emotions and feelings, or to learn that our thoughts create "reality." We may be creating different experiences and lifetimes for fun - like gods playing throughout the universe. And if time is simultaneous, that suggests that you are having all these different lifetimes at the same time. So they are "other lives" not "past lives."
There are many different theories and beliefs about this subject. You're free to decide for yourself. What an interesting subject though, isn't it? Just another topic to make us think about life and who we are. We can't possibly believe we know EVERYTHING about life or reality. For those who don't believe reincarnation is real - that's okay too. We each have different ways to see life and experience reality. If you think there is no scientific research being done on topics such as these - you haven't been doing your homework. Science - especially quantum physics - is stating amazing things about "reality" that we didn't know about before. For example, check out the work being done on "parallel universes" - just for a start. The research being done by physicist David Deutsch is a good place to start.
We are learning new things all the "time." Or do we actually already know all of this - we're just pretending to forget so we can have fun and play with different experiences? After all, we go to the movies or watch TV just for fun - to have different experiences and feelings. We seem to be playful beings - maybe that is what life is about, the reason we exist?