type, the object with the highest measured amplitude is young – so there is the possibility that the highest intrinsic amplitudes occur in young objects, and that the observed amplitudes can be reduced by secondary effects such as inclination angle [@Vos2017].

![image](amplitude_spt_ch1-eps-converted-to.pdf) ![image](amplitude_spt_ch2-eps-converted-to.pdf)

The right panel of Figure \[fig:amplitudes\_plot\] shows the amplitudes of $4.5~\mu$m variability detections as a function of spectral type. For early-L spectral types, the young population shares similar amplitudes with the field brown dwarfs. In the late-L population, the four young $\sim$ L7 objects PSO J318.5-22 [@Biller2018], WISEA 1147-2040, 2MASS 1119-1137AB [@Schneider2018] and VHS1256-12b [@Bowler2020; @Zhou2020] show enhanced amplitudes compared to the field population. Note that since 2MASS 1119-1137AB is a binary system [@Best2017], its peak-to-peak amplitude of $0.96\%$ is likely underestimated since the variability signal may be diluted by its unresolved companion. In the near-IR there seems to be a distinction in the behaviour of late-L young brown dwarfs compared to field brown dwarfs. While older mid to late-L dwarfs [@Yang2016; @Manjavacas2018] show a linear amplitude dependence on wavelength, the young objects PSO J318.5$-$22 [@Biller2018], WISEP J004701.06$+$680352.1 [W0047, @Lew2016] and HD203030B [@Miles-Paez2019] show different amplitudes in the water absorption band at $1.4~\mu$m. PSO J318.5$-$22 and W0047 