Behavioral differences between members of the same family

In my post yesterday entitled Mongrel genes, I spoke of a curious change of behavior between a recent Skyvington father and his son. Well, no matter how hard I try to follow up this question on the web, I simply cannot understand how enormous behavioral differences might affect members of a single family. Explanations evoke inevitably the question of nature versus nurture. But I still fail to grasp the reasons why members of my own family group appear to be so different.

I grew up essentially in the same environment—indeed, in the same houses—as my brother and sisters, in simple rural settings, in similar educational contexts and social circles. But I have the impression that I evolved in totally different directions to my siblings. I often feel that I was "hit by a dose of mongrel genes", which have made me a very different individual to my siblings. For the moment, I simply fail to understand how these differences could have come about. I continue to believe, rightly or wrongly, that they were differences of nature rather than of nurture. But this opinion could well be erroneous.

In any case, I have no recollections of ever getting involved in "philosophical" discussions with specific adults, be they teachers or religious folk. The only individual whose remarks often sent shivers up my spine was my maternal grandmother, whom we called Grandma. She often analyzed critically the personality of my father, suggesting that he was what we might call "bipolar", constantly alternating between one kind of behavior and its opposite. Grandma used a mixed-up metaphor, saying that "the worm would turn". I think he meant that Dad was capable of abruptly reversing his personality. It's a metaphor that even Shakespeare used, but nobody knows its exact origins. Somebody suggests that the worm was a dragon, and that his "turning" simply meant that the beast was no longer about to attack us.

Grandma had lost her beloved husband Charles Walker [1882-1937] when he was still a relatively young man.

I often felt that this premature departure of her husband had destabilized the poor lady, and caused her to adopt a constantly harsh outlook on human existence. Grandma would go out of her way to make me realize that my own dear mother Kath could rapidly find herself placed "in the clay up on the hill at South Grafton" (that is, the local cemetery).

In another situation, Grandma plunged me into a state of despair when I saw her reacting most negatively to the fact that Bill, Kath and our family had failed to make a point of communicating with her when we traveled on vacation up around the Northern Tablelands. Because of our failure to communicate, Grandma said that she no longer wished to hear any words about our supposedly happy holiday. This austere character existed also in her elder sister Henrietta. Besides, let us not forget that these ladies were essentially descendants of Irish Protestants.

Is it imaginable that Grandma was transforming me when I was still a child, as it were, into the objective thinker that I would soon become ? It's certainly a highly recognizable case of nurture that cannot be denied.