GRE Verbal Reasoning practice: section 1

One might expect regional differences in birdsong to be inherited, much as differences in plumage are. In many songbirds, however, experiments show otherwise. Young males raised without hearing adults of their own species develop a simplified song that keeps some features typical of the species but none of the local detail, while those that hear only the songs of adults from another region acquire that region's song instead of their parents'. Song dialects, in other words, are passed on by learning.

Yet learning does not make song endlessly flexible. In many species a young bird copies readily only during a limited period early in life, and only from models whose song falls within the range its species is predisposed to learn. Dialects can therefore persist for many generations, even though no bird is born knowing one.

In one city, residents who borrow books from the public library at least once a month score higher, on average, on a standard reading test than residents who rarely or never borrow books there. The city council concludes that borrowing library books improves reading skills. It therefore plans to extend the library's opening hours, expecting that more residents will borrow books and that the city's reading skills will rise as a result.

It is tempting to tell the history of standard time as a story of technology imposing its logic on everyday life. Before the railways, each town set its clocks by the local position of the sun, so that noon in one town fell a few minutes earlier or later than noon in the next. Trains that crossed many such towns in a day could not be timetabled against dozens of local clocks, and so, the story goes, the railways forced the world onto a common time.

The record suggests something messier. In Britain, most railway companies had adopted Greenwich time by around 1850, but Parliament did not make Greenwich Mean Time the legal time for Great Britain until 1880, and in the meantime it was not unusual for a town's station clock and its church clock to disagree. In North America, the railroads of the United States and Canada introduced a shared system of time zones in 1883, yet the United States did not write time zones into federal law until 1918. In Britain and the United States alike, then, the law ratified a practice that had already spread rather than creating it. And the practice spread unevenly: some cities went on keeping local time for years after the railroads changed, and some critics objected to letting railway companies set the hour for everyone.

None of this means that the railways were unimportant. It means that their influence worked through the choices of people who weighed the convenience of a common time against local custom, and who did not all weigh it the same way.