I don't believe each life starts with a clean slate.
Eze 18:1 The word of the Lord came to me:
2 What do you mean by repeating this proverb concerning the land of Israel, “The parents have eaten sour grapes, and the children’s teeth are set on edge”?
3 As I live, says the Lord God, this proverb shall no more be used by you in Israel.
4 Know that all lives are mine; the life of the parent as well as the life of the child is mine: it is only the person who sins that shall die.
The Spirit goes on explaining this in the rest of the chapter.
How else would the prayers of parents and grandparents have any effect? Similarly the curses from the behaviours of ancestors can be inherited. So we inherit the curses and blessings of past lives including Adam at conception.
What you mean in the 1st sentence is not clear to me. But generally, the effects of blessings and curses can be exhibited in the following generations through their material and psychological effects, not through genetic inheritance. For example, one may experience the effects of their parents wealth or education or friendships, and the opposites of these would be poverty, lack of education, abuse, etc.
Have you never heard testimony of, for example, accident proneness being prevalent in previous generations being broken off the present generation?
The concept of accident proneness has had a long and controversial history. Statistical evidence clearly demonstrates that different individuals can have different rates of accidents from one another. The studies have revealed that
educational background or study experience is the key factor of concentration capability.
Accident-proneness - Wikipedia
Everything I wrote is about physical and psychological explanations. But you seem to have spiritual explanations in mind.
There could be spiritual forces beyond my understanding. And I'm interested in hearing your experience.