The phrase "a tendency to act" is correct and usable in written English.
It can be used when discussing someone's habitual behavior or inclination towards a specific action or response.
Example: "She has a tendency to act impulsively when faced with difficult decisions."
Alternatives: "a propensity to behave" or "an inclination to respond".
When he talks, he has a tendency to act out his anecdotes.
At times like these, there is a tendency to act now and ask questions later.
He early displayed a tendency to act over the heads of his ministers, especially in regard to foreign affairs.
The United States and Russia are both led by men with fragile egos and a tendency to act impulsively.
Some experts speculate that what is inherited is impulsivity, a tendency to act on aggressive urges without thought to the consequences.
Yet there's often a tendency to act as if the constructivists were themselves "western" in the cold war sense – that they were typical creative types who couldn't be encompassed into the "system".
Thanks mainly to Davina having a different body from Nicola, a different gait from Nicola and a bizarre tendency to act like the world's most comically exaggerated French mime artist whenever she gets within 30 feet of a chicken suit.
The DFT calculations of piperidine adduct reveal a smaller HOMO LUMO energy gap than morpholine adduct, suggesting that piperidine adduct has a greater tendency to act as an electron donor.
One might speculate whether Norwegian children react with more emotional symptoms as a response to neglect and abuse, while British children respond with a stronger tendency to act out.
The American attitude in part reflects the natural resistance of the world's last superpower to sharing sources and methods and, some in Europe fear, a growing tendency to act unilaterally.
It is non-cognitive, because it is essentially a motivational tendency to act or feel in ways that we are prepared to avow in discussion about what to do.
