Appearances can be deceiving.

Even as the economy decelerated last quarter, mostly because of more cautious stockpiling by companies as economic turmoil overseas intensified, the American consumer kept right on spending. And most American businesses, in making their longer-term investment decisions, weren’t far behind.

While the overall rate of growth was a decidedly lackluster 1.5 percent last quarter, according to the Commerce Department report on Thursday, spending by consumers on goods like furniture and services like health care and insurance advanced at more than twice that pace.

“The good news is that the important engine of personal consumption remains strong,” said Scott Clemons, chief investment strategist at Brown Brothers Harriman. “The headline data was slightly disappointing, but the persistent strength of personal consumption bodes well for a continued modest expansion in the U.S. economy.”

The tempo of growth over the summer, which was in line with analysts’ expectations, represented a marked drop from the 3.9 percent pace of expansion in the spring.