Uri has personality traits that could be described as honest, hardworking, and humble; his wife has described his chief temperamental trait to be shyness. Of all these traits, the one that could be considered primarily genetic would be:
shyness.

Shyness personality traits

Explanation:

Shyness is a trait similar to social anxiety disorder but in very less quantity. This is difficult for shy people to adapt or adjust in that environment that is dominated by extrovert people. But for shy people, it is easy to come down to earth if he/she is a famous personality.  

There is some proposition about shy people:

shyness

Explanation:

Shyness -

It refers to the personality of the person , who is very humble , honest , less confidence and hardworking , is referred to as shyness .

A shy person tends to keep quiet and concentrate on his or her work only , rather than interfering into other person's work .

Hence , from the given scenario of the question ,

The correct answer is shyness .

question - in 1827, john walker, a druggist in a small english town, tipped a splint with sulphur, chlorate of potash, and sulphid of antimony, and rubbed it on sandpaper, and it burst into flame. the druggist had discovered the first friction-chemical match, the kind we use to-day. it is called friction-chemical because it is made by mixing certain chemicals together and rubbing them. although walker's match did not require the bottle of acid, nevertheless it was not a good one. it could be lighted only by hard rubbing, and it sputtered and threw fire in all directions. in a few years, however, phosphorus was substituted on the tip for antimony, and the change worked wonders. the match could now be lighted with very little rubbing, and it was no longer necessary to have sandpaper upon which to rub it. it would ignite when rubbed on any dry surface, and there was no longer any sputtering. this was the phosphorus match, the match with which we are so familiar. according the paragraph what was the benefit of the new phosphorus match? it burst into flame when rubbed on sandpaper. it was made by mixing chemicals. it could be ignited on any dry surface. it threw fire in all directions.

answer - matches required natural chemicals