Some workers experience difficulties on account of their age in keeping or obtaining employment. Although the ageing processes advance at different speeds in different individuals, most people reach their peak, physically and mentally, between the ages of 25 and 30, and thereafter decline. Manual skills are at their maximum at an even younger age. Decreasing abilities may be at least partially offset by increasing stamina, experience, and common sense. However, the chance of illness also increases with age.
There are many misconceptions about the efficiency of older workers: they are inflexible, lack energy, do not keep up with the latest developments in high-technology, cost more to employ, are more subject to ill health, are less productive. These misconceptions, even when unfounded, lead to discrimination against older people in employment. While it is true that, in many countries, employer contributions to social security are higher for older than for younger workers, giving rise to the assumption that older workers are less cost-effective than younger ones, research shows that training older workers is often more cost-effective than training younger ones, because the older workers are more receptive and attentive.
Discrimination against older workers can take many forms. In some countries, where decreasing numbers of young people are coming into the job market, companies are recruiting older people, but generally for part-time, or second class jobs: this is a more sophisticated form of discrimination.
In the USA 40 is the age at which employees can bring lawsuits under federal employment law claiming age discrimination in the workplace. About 45% of American workers are now 40 or older.