In discussing the relatively low rate of contraction in Charles Portis's novel True Grit, I suggested several different explanations. It might be false archaism, or it might be a way to bring out the personality of the narrator, Mattie Ross. Another option, of course, would be that it's a quirk of the author's style. We can eliminate this last possibility by checking another of his novels, Norwood, which (according to Wikipedia)
… follows its namesake protagonist on a misadventurous road trip from his hometown of Ralph, Texas, to New York City and back. During the trip, Norwood is exposed to a comic array of personalities and lifestyles. The novel is a noteworthy example of Portis' particular skill rendering Southern dialect and conversation.
The only easy way to estimate contraction rates is to use the page-counts in Google Books, which gives us the following counts and percentages:
|don't/do not||105/2 (98%)||14/11 (56%)|
|won't/will not||14/1 (93%)||6/6 (50%)|
|wouldn't/would not||24/1 (96%)||1/11 (8%)|
|it's/it is||56/23 (71%)||2/21 (9%)|
|that's/that is||56/3 (94%)||2/17 (11%)|
|I'm/I am||68/9 (88%)||0/26 (0%)|
You may notice that the counts are somewhat different from those I gave in my earlier post. This reflects the bizarre and puzzling non-determinism of Google Books. Thus when I checked yesterday evening, GB told me that True Grit had 5 pages containing won't and 9 containing will not — this morning it tells me that the counts are 6 and 6. Yesterday evening, True Grit had 12 pages containing don't and 8 containing do not — this morning, it has 14 and 11 respectively. And so on. But despite these peculiarities, I'm going to trust that the large reported differences in contraction-percentage between Norwood and True Grit are real.
The contraction rates estimated for Norwood are simiar to those that we saw in Tom Sawyer and Swan Peak. And the distribution of variants also follows the sociolinguistic patterns that we expect: for example, the only two examples of "do not" in Norwood are these:
… and took down the "I Do Not Loan Tools" sign from the persimmon tree.
… although the signs said DO NOT TALK TO OPERATOR he started right in cracking jokes and carrying on with the passengers.
So I conclude that the low contraction rates in True Grit represent an artistic choice by Portis. Unfortunately, none of his other novels are set in the 19th century, so we can't determine whether he believed that people talked differently in this respect back them, or simply felt that lower contraction rates suited Mattie. Since they do, I'm going to give him the benefit of the doubt on this.