High residential property prices and tighter underwriting standards for investor mortgages have not dampened investors' enthusiasm for property investment, according to new research.ING Direct's latest Financial Wellbeing Index shows that the proportion of adult Australians who own an investment property has increased from 17 per cent to 20 per cent over the past year. Six per cent own two or more investment properties.Surprisingly, 22 per cent of Gen Y (people aged 18 to 34) own investment property. This is the group that is supposedly finding it hard to break into the property market.