Very tribalistic
While there may be some genetic mixing, your clone has to be pretty much the same dimensions as you. I'd imagine most phenotypes would be shared between the two. More importantly, if memories are carried over it stands to reason that dogma is transferred over from birth. Wrongdoing from generations ago could carry over as what feels like first-hand memories, but with much more time to diverge from the truth. While in the real world children are taught who the enemy is in this world everyone knows from birth. At the same time, everyone from the other tribe also carries memories of traumatic events (albeit likely very different from yours). While most people consider it wrong to harm children for the wrongdoing of their families no one in this world is ignorant of history and everyone in a lineage may be considered responsible.
Fewer, but more intense taboos
We're all adults here everyone is mature enough to curse and talk about reproduction. That said if something is taboo everyone already knows from birth taboos never need to be explained or discussed unless of course, you aren't part of our lineage. A very big difference from humans is that people could potentially remember their birth perhaps the moment of splitting. This could be a more celebrated moment like human birth or something done behind closed doors like sexual reproduction. Either way, there would likely be all kinds of ritual and taboo surrounding it.
Highly optimised, but less revolutionary
It's diffuicult to say how the tasks of a person are delegated to the two new people however it's very likely that they would pick right where they left off. Perhaps the siblings will work together or perhaps they will take on different interests (finally get to start that rock band!). Because memories are kept, there is no training needed for a newborn to get to work which will allow larger projects to be completed faster and with more consistent vision. If the siblings work together they would likely have great synergy starting off with the same amount experience (built over generations) and an intimate understanding of each other.This combination of expertise and solid teamwork would lead to highly optimised products and more success in feilds like math where problems can take generations to solve and many years to even understand. 335
That said with such levels of experience, it would be hard to break into a field or industry which can cuase stagnation. Siblings could prevent this by tag teaming. One works and the other goes on a sabbatical then when the working sibling burns out they switch places to bring a new perspective while minimising the amount of time need to learn the ropes. This can be extended to the whole family tree with a variety of degrees of involvment that regularly changes in accordance to experience, and fresh perspectives (which are somewhat opposed and both inherited) like a royal bloodline however it would be built on experience and knowledge retained making it more utilitarian than human bloodlines. This provides plenty of opportunities for factions and rivalries forming feeding right back to tribalism.
Not into cuteness or dating
Childhood and parenthood are incredibly important to forming familiar bonds. Without childhood, relationships in this world would probably built on generations of interaction more along the lines of a fellow countryman. There would be no maternal instinct and no sense of cuteness so say goodbye to Hello Kitty. Without sexual reproduction, there would be no biological drive for romantic relationships. That's not to say there would be no romantic relationships just that they wouldn't be common and may even be frowned upon. Romantic relationships are unlikely to be codifed with concepts like staying faithful or being committed so each relationship would be unique in it's expectations rather than falling into defined categories like dating, boy/girlfriend, and married. It's also important to remember that eventually your significant other will split in half if they don't die first so dating is either short lived or very open. I'd like to mention that people would probably have a weak sense of individuality since they carry the memories of past lives and know that their body and mind will be split and morphed. A sense of self is very important to forming personal relationships so they wouldn't be very common. Overall, the lineage comes first.
Hope this helps best of luck! 1008