ideas for variable with branching data?
The typical way to address this is to transform those characteristics into a representation where you compose a vector with one component for each possible characteristic, with a $1$ in the position of each characteristic owned by the individual, or zero otherwise.

This way, you would have:


name | greedy | smart | funny | sad | prideful | stupid | ... | score
----------------------------------------------------------------------
John |   1    |   1   |   0   |  0  |    0     |   0    | ... | 0.8
Ann  |   0    |   1   |   1   |  1  |    0     |   0    | ... | 0.6
Joel |   1    |   0   |   0   |  0  |    1     |   1    | ... | 0.2