The word "fixedness" is correct and usable in written English.
It is typically used to describe a state of being fixed or unchanging, often in a psychological or philosophical context.
Example: "The fixedness of her beliefs made it difficult for her to consider alternative viewpoints."
Alternatives: "Inflexibility" or "Rigidity."
When one is faced with a new problem, functional fixedness blocks one's ability to use old tools in novel ways.
Overcoming functional fixedness first allowed people to use reshaped coat hangers to get into locked cars, and it is what first allowed thieves to pick simple spring door locks with credit cards.
Some of the more common obstacles, or blocks, are mental set, functional fixedness, stereotypes, and negative transfer.
Functional fixedness is the inability to realize that something known to have a particular use may also be used to perform other functions.
This gives the hobby of raising homing pigeons a curious permanence, a fixedness in space.
(Monaghan's fixedness on abortion prompted him, in December, to join the exploratory committee for what would be the long-shot Presidential campaign of Senator Sam Brownback, who is steadfastly pro-life).
There are academic debates about the singularity, accuracy, and fixedness of these memories — and the two men on the corner, researchers from the New School University, were joining these debates with a thirteen-page questionnaire entitled "Your Reactions to the Recent Terrorist Attack".
Lindsey said she understood the position of those advisers (including her husband), because she had dealt with Hillary's fixedness, though on less momentous issues, when she was doing scheduling for her during the Presidential campaign.
Rumsfeld came into office, in his second tenure as Secretary of Defense, as a man who had seen much and believed that he knew much, and he just wasn't in the mood to brook a lot of what he considered to be nonsense: bureaucratic institutional fixedness, a devotion to old ways and to old weapons systems, and old lassitude, in the case of the Army.
Misal, like the students he taught, was in revolt against the old fixedness.
