If an individual shows all six clues during the HGN test, what does it suggest?

When an individual demonstrates all six clues during the Horizontal Gaze Nystagmus (HGN) test, it indicates a high likelihood of significant alcohol impairment. The HGN test assesses the smoothness of eye movement and identifies involuntary jerking (nystagmus) that occurs when the eyes are moved laterally. The presence of all six clues—such as noticeable nystagmus at maximum deviation and possible failure to smoothly follow a moving object—provides strong evidence of impairment due to alcohol.

This correlation is supported by research indicating that the probability of a blood alcohol concentration (BAC) exceeding a certain threshold increases significantly with the number of clues exhibited. Therefore, displaying all six clues is a critical indicator that the individual is likely to be under the influence of alcohol to a substantial degree, aiding law enforcement in making informed decisions regarding impairment.