intuitive

Nowadays, we often see intuitive used in contexts pertaining to technology that is easy to understand. A smartphone with an “intuitive interface” is one that doesn't need much explaining; you can usually figure out how it works as soon as you fire it up.

The related noun intuition, meanwhile, describes a feeling of knowing or understanding something without evident rational thought and inference. A parent's intuition might tell him or her that a child is in danger, even if there is no logical reason to believe so.

So does intuitive have anything to do with what is often called the sixth sense? Well, the sixth sense is defined as "a keen intuitive power." It is synonymous with ESP or extrasensory perception. As its name implies, ESP describes a purported ability to know something that cannot be known by normal use of the senses.

The Swiss psychologist Jean Piaget (1896-1980) used the term intuitive substage to refer to the stage of cognitive development when children have acquired a vast amount of knowledge but have not considered how they acquired it, so they accept it as true.

An interface is intuitive because it makes sense according to what we expect from how older interfaces are designed. A parent's intuitive sense of danger may still be prompted by subtle hints that things just aren't as they should be, even if the parent cannot identify exactly how. So while sixth sense refers to the ability to acquire knowledge from beyond the five senses, intuitive tends to apply more to knowledge absorbed through experience, even when not immediately recognized as such.