As a general rule what percentage of debt to gdp will make a government bond yields spike

There is no general debt-to-gdp ratio rule because a bond yield depends on many other factors, not only on debt-to-gdp ratio.

For example, the United States has a very high debt-to-gdp ratio of over 100%, but the US bond is considered to be the safest bond in the market, has a high credit rating of AA+ according to Firtch, Moody's and S&P, and is a cheap bond because interest rates in the US are low, so the coupon payments are low as well.

The yield to maturity of a 10 year US bond is around 2%. Therefore, what all this information is telling us, is that even if debt-to-gdp ratio in the US continues to increase, the US bonds yields will probably continue to be stable. They will not spike because the debt-to-gdp ratio increases.

cognitive overload: having a lot on your mind impairs decision-making and tends to result in the simplest, but not necessarily best, option being selected.

empathy gaps: overlooking how you might feel in a different situation can result in unnecessary purchases, such as overbuying when shopping for food on an empty stomach.

optimism and overconfidence: wearing rose-tinted glasses and having unrealistic expectations about the future can affect money management and leave you unprepared for a change in circumstance.

instant gratification: seeking instant gratification drives impulsive spending and can undermine long-term planning and savings.

harmful habits: automatic or mindless behaviour can amplify a poor financial decision as it becomes a recurring event.

social norms: we are heavily influenced by the actions of others; while this can be in certain circumstances, it also contributes to the pressure to keep up with the joneses through conspicuous consumption.