What is the usage of tenses in this paragraph?

Question

I have a misunderstanding of usage of the tenses in this paragraph:

He didn't know what to make of his younger son. He'd thought they'd been close. He'd made a special effort to spend time with Jack while he was growing up. An unplanned baby. He and Jane had their boy and their girl and were content with that. But Jack showed up eight years after Kate, and neither Tom nor Jane had quite the energy they'd had with the first two. But Tom hadn't wanted to shortchange the little guy, thus the special effort.

F. Paul Wilson - Gateways

1). The narration in the sentence "He and Jane had their boy" and it the following sentences takes place in the earlier period that the one in the first sentence (when Jane is already dead). Why does the author use present simple but not present perfect? Is it correct to suddenly change the current time during narration?

2). "But Tom hadn't wanted..." When exactly he hadn't wanted? When he didn't know what to make of his younger son, when he and Jane had their boy or when they didn't have quite the energy?

Answer 1

The change to past tense isn't wrong (this is still a past action). You can argue that the author should have started a new paragraph. (You can also argue that the author should have avoided the sentence fragment "An unplanned baby".)

Tom hadn't wanted to give his youngest son less than his other children (to metaphorically shortchange him), presumably this was from as soon as he knew that his wife was pregnant, but at least from the time when he realised that if he didn't make a special effort, he would "shortchange him".

I think you are trying to read too much into the use of tense here, and losing sight of the plain meaning. Looking at the wider context, it seems that the author is narrating the slightly disturbed thoughts in the father's head, and there is a deliberately disorienting lack of a simple chronological narrative (but this is moving from English Learning to literary criticism)