Michael Vaughan launched a scathing attack on English cricket just moments after seeing his side crushed by South Africa on Monday, arguing its players were weighed down by fear.
The England captain, whose side lost the fourth test by 191 runs at Headingley despite appearing to hold the upper hand on several occasions, said: "Why did we lack ruthlessness? It's a good question. England teams have been similar in recent seasons.
"Perhaps it's mental, perhaps it's attitude, the way we are brought up in the game. Maybe it's fear.
"County cricket is not producing mentally tough players. It needs to be looked at."
England reduced South Africa to 21 for four on the opening morning and 142 for seven later in the day but could not kill off the first innings as the last three wickets added 200 runs.
The home team then failed to take a first-innings lead after reaching 169 for one and their bowlers also missed out in the second innings as South Africa added 205 for their last five wickets.
"From 142 for seven, you shouldn't allow them to get 365," Vaughan, whose side trail 2-1 in the series with one test left, added.