As people rely more and more on technology to solve problems, the ability of humans to think for themselves will surely deteriorate.
I consider the whole statement is not true, although in some cases it seems to be true. For me as an engineer, there is lots of software that I could use them for solving my problems. These problems usually contain solving numerous equations that I can't do them with hand because of their difficulty or maybe they need numerical solving that needs solving millions of equations. So I need a calculation tool. These tools are different software.
For solving a problem by these kinds of software, I should know about the physics of problem, method of solving it, background equations, constants that I can use and also know about which conditions I should enter and which the software considers. So the software is usable for only the person who knows the phenomena.
A school student who doesn't know anything about equations couldn't use this software at all. An engineer who just knows a little about equations and constants could solve a problem by software, but just he could solve problems that the procedure and methods of solving and constants you need were prepared formerly from any resource. But if you ask him a different question or change the conditions of solving problem, he couldn't solve it because he didn't understand the phenomena.
These tools just deteriorates the ability of thinking for some people who their work is routine and don't need any change in problem, in this case I consider that solving problem by hand, makes them to use their mind. But this is a rare case. And usually when a person needs to solve a problem with these tools, needs to be creative too. So he should think to find new and innovative methods for solving problem.
I think that these technological tools just deteriorate the ability of calculation and I don't mind about it at all. Because I can solve very hard problems in hours that normally may take years. It is worth a lot, isn't it?